Jump to content

07/08 Tahoe Tsb Help Sought


Beemie

Recommended Posts

Posted

I also posted this in the general light truck section before realizing it may belong here, so forgive the double posting.

 

I am looking to learn what the Technical Service Bulletin #06-03-10-001E AUG07 and 05-03-10-005C Aug07 say about wheel and tire upgrades for 2007/2008 4 wd, 5.3 Tahoe.

Posted

Document ID# 2002094

--------------------------------------------------------------------------------

Subject: 20 Inch and 22 Inch Accessory Wheels Available Through GM Accessories #06-03-10-001E - (08/06/2007)

 

Models: 2007-2008 Cadillac Escalade, Escalade ESV, Escalade EXT (20" and 22")

2007 Chevrolet Avalanche, Suburban (1500 Series), Tahoe (Excludes Police Package PPV) (20" Only) (Excludes Vehicles with Off-Road Appearance Package RPO BPH Built Prior to and Including the VIN Breakpoints Below)

2008 Chevrolet Avalanche, Suburban (1500 Series), Tahoe (Excludes Police Package PPV and Hybrid Package HP2) (20" and 22")

2007 GMC Yukon, Yukon XL (1500 Series) (20" Only)

2007-2008 GMC Yukon Denali, Yukon Denali XL (20" and 22")

2008 GMC Yukon (Excludes Hybrid Package HP2), Yukon XL (1500 Series) (20" and 22")

--------------------------------------------------------------------------------

This bulletin is being revised to add 2008 model year. Please discard Corporate Bulletin Number 06-03-10-001D (Section 03 -- Suspension).

--------------------------------------------------------------------------------

Plant

Plant Code (VIN Position 11)

VIN Breakpoint

 

Arlington

R

7R386644

 

Silao

G

7G288891

 

 

The purpose of this bulletin is to provide a reference guide for the technician to upgrade a vehicle from factory wheels and tires to 20" or 22" wheels and tires, which are available through GM Accessories. This guide will cover the required vehicle modifications, module reprogramming and warranty information.

 

Important: 20" and 22" accessories wheels released for 2007 model year full-size utilities are NOT compatible/interchangeable with pre-2007 model year full-size trucks and utilities and vice versa. GM accessories wheels are validated and released for specific vehicle applications. In this case, a difference in wheel offsets exists between the different model years. Warranty coverage and dealer indemnification will not be provided in situations relating to incorrect application usage.

 

Vehicle Modifications

Tires (20")

GM offers two tires, the Bridgestone Dueler H/L Alenza P275/55R20 or the Goodyear Eagle LS2 P275/55R20, to be used in conjunction with the 20" accessory wheels. The Bridgestone Dueler and Goodyear Eagle tires have a Tire Performance Criteria (TPC) spec of 1245MS (molded on the sidewall) which meets or exceeds all Federal Safety guidelines.

 

Tires (22")

GM offers two tires, the Bridgestone Dueler H/L Alenza P285/45R22 or the Goodyear Fortera SL P285/45R22, to be used in conjunction with the 22" accessory wheels. The Bridgestone Dueler tire has a Tire Performance Criteria (TPC) spec of 1261MS (molded on the sidewall) and the Goodyear Fortera has a Tire Performance Criteria (TPC) spec of 1344MS (molded on the sidewall), both meet or exceed all Federal Safety guidelines.

 

Important: When mounting the tires, rubber lubricant, P/N 12345884 (in Canada, 5728223), must be used. Also, the vehicle should not be driven aggressively (hard acceleration or braking) for at least 6-8 hours after tire mounting to allow the lubricant to dry. Failure to do so may cause the tire to slip on the rim. This condition will affect wheel balance which could result in a vibration.

 

Tire Label

Important: All 20" tire and wheel packs are shipped with two different tire labels. Use tire label P/N 19165889 (road tire pressure of 32 psi) for the models listed in this bulletin.

 

After installing the recommended tires, place the provided tire label on the vehicle. The new tire label should be located within the red box, over the top of the original tire label found on the door jamb. To locate the label within the red box use the upper left hand edge of the red line as a guide. When properly placed, the new tire label will obscure the original tire information. Be sure that the surface is clean and dry. The surface temperature should not be less than 21°C (65°F). The label is provided as a guide for tire inflation pressures and information relevant to occupant/cargo capacities.

 

Tire Type/Pressure Selection

To provide a more accurate function of the Tire Pressure Monitoring System, it is necessary to update the Remote Control Door Lock Receiver (RCDLR) with the correct tire type and pressure information. Using the Tech 2®, follow the steps listed below to select the appropriate tire type/pressure:

 

Install the scan tool.

Turn ignition ON with engine OFF.

Enter "Diagnostics" and build vehicle according to model year, vehicle line, etc.

Select "Body."

Select "RCDLR Module."

Select F2: Module Setup.

Select F5: Tire Type/Pressure Selection.

Select P-Metric Standard.

Select the front and rear tire pressure as noted on the new vehicle driver door placard sticker for the accessory wheels/tires.

Verify that the selections made are correct and press the enter key. The scan tool will flash "Procedure in Progress", then display "Procedure Complete."

Press the "exit" key to escape.

Tire Pressure Monitor (TPM) System

Important: Tire pressure sensors for 2007/2008 model year full-size utilities are not compatible/interchangeable with pre-2007 model year full-size trucks and utilities and vice versa.

 

To avoid system malfunctions, it is necessary to install tire pressure sensors in the accessory wheels. Replacement sensors can be obtained or sensors from the OE wheels can be transferred to the accessory wheels. After the wheels are installed on the vehicle, it is necessary to learn the new sensor identification codes/locations into the remote control door lock receiver (RCDLR).

 

TPM Sensor Relearn Procedure

 

Important: Before proceeding, ensure that no other learn procedure is being performed simultaneously or that tire pressures are not being adjusted on another TPM equipped vehicle within close proximity. Stray signals from other TPM equipped vehicles just driving by can be inadvertently learned. If any random horn chirps are heard from the vehicle while performing the learn procedure, most likely a stray sensor has been learned and the procedure will need to be cancelled and repeated. Under these circumstances, performing the TPM Learn Procedure away from other vehicles would be highly recommended. In the event a particular sensor pressure increase/decrease activation does not cause the horn to chirp, it may be necessary to rotate the wheel valve stem to a different position due to the sensor signal is being blocked by another component.

 

Place the ignition switch in the proper position as follows:

• With standard ignition switch, place the switch in the RUN position.

• With electronic keyless ignition, place the switch in the ACCY position.

Initiate the TPM Learn Mode using one of the following procedures:

• Using a scan tool, initiate the TPM Learn Mode. A double horn chirp will sound indicating the Learn Mode has been enabled. The left front turn signal will also be illuminated.

• On vehicles equipped with keyless entry, simultaneously press the keyless entry transmitters lock and unlock buttons until a double horn chirp sounds indicating the Learn Mode has been enabled. The left front turn signal will also be illuminated.

• On vehicles not equipped with keyless entry, press and release the driver information center (DIC) INFO button until the RELEARN TIRE POSITIONS message appears on the DIC display. Press and hold the SET/RESET button until a double horn chirp sounds and the DIC displays a TIRE LEARNING ACTIVE message indicating the Learn Mode has been enabled. The left front turn signal will also be illuminated.

Starting with the left front tire, learn the tire pressure using one of the following methods:

• Hold the antenna of the J 46079 aimed upward against the tire sidewall close to the wheel rim at the valve stem location. Press and release the activate button and wait for a horn chirp. Once the horn chirp has sounded, the turn signal in the next location to be learned will illuminate.

• Increase/decrease the tire pressure for 8-10 seconds then wait for a horn chirp. The horn chirp may occur before or up to 30 seconds after the 8-10 second pressure increase/decrease time period has been reached. Once the horn chirp has sounded, the turn signal in the next location to be learned will illuminate.

 

After the horn chirp has sounded and the right front turn signal is illuminated, repeat step 3 for the remaining 3 sensors in the following order:

4.1. Right front

4.2. Right rear

4.3. Left rear

After the LR sensor has been learned, a double horn chirp will sound indicating all sensors have been learned.

Turn OFF the ignition to exit the learn mode.

After the learn mode has been exited, adjust all tires to the recommended pressures indicated on the new tire label.

Spare Tire Hoist (22" Wheels Only)

Important: The new spare tire hoist is necessary due to the added amount of stress that the 22" wheel/tire system causes to the factory installed tire hoist. The tire hoist is also needed even if you do not put a 22" spare under the vehicle.

 

Replace the spare tire hoist with P/N 19158309. This modification is required for the following vehicles when installing 22' wheels.

• 2007-2008 Cadillac Escalade

• 2007-2008 Cadillac Escalade ESV

• 2007-2008 Cadillac Escalade EXT

• 2007-2008 GMC Yukon Denali

• 2007-2008 GMC Yukon Denali XL

• 2008 Chevrolet Avalanche

• 2008 Chevrolet Suburban

• 2008 Chevrolet Tahoe

• 2008 GMC Yukon

• 2008 GMC Yukon XL

 

The following procedure should be followed for this modification.

 

If the vehicle is equipped with a spare tire stowage lock cylinder, open the spare tire lock cover on the bumper and using the ignition key, remove the lock.

Rotate the hoist shaft counterclockwise in order to lower the spare tire to the ground. Continue to rotate the shaft until the spare tire can be pulled out from under the vehicle and removed. If the spare tire does not lower to the ground, the secondary latch is engaged causing the tire not to lower.

If the secondary latch is engaged and the cable end is visible, perform the following procedure:

3.1. Tighten the cable by rotating the hoist shaft clockwise until you hear two clicks or feel it skip twice. You cannot overtighten the cable.

3.2. Loosen the cable by rotating the hoist shaft counterclockwise 3 or 4 turns.

3.3. If the spare tire can be lowered, repeat steps 1 and 2 to see if the spare tire can be removed.

3.4. If the spare tire cannot be lowered, rotate the hoist shaft counterclockwise until approximately 152 mm (6 in) of cable is exposed.

3.5. Raise and support the vehicle.

3.6. Place a transmission jack, or equivalent, under the spare tire.

3.7. Position the center of the transmission jack under the secondary latch release button at the center of the spare tire. Arrange the arms of the transmission jack so they will support the tire after it has been released.

3.8. Raise the jack until the spare tire stops moving upward and is firmly held in place, releasing the secondary latch.

3.9. Lower the tire. If the spare tire is hanging by the cable, rotate the hoist shaft counterclockwise until the tire is low enough to remove.

If the secondary latch is engaged and the cable end is NOT visible, perform the following procedure:

4.1. Raise and support the vehicle.

4.2. Place a transmission jack, or equivalent, under the spare tire.

4.3. Position the center of the transmission jack under the secondary latch release button at the center of the spare tire. Arrange the arms of the transmission jack so they will support the tire after it has been released.

4.4. Raise the jack until the spare tire stops moving upward and is firmly held in place, releasing the secondary latch.

4.5. Lower the tire and remove it from the jack.

Raise and support the vehicle if it is not already raised.

Depress the tabs, remove the guide shaft from the hoist collar, and slide the shaft toward the bumper.

Remove the collar from the hoist.

Remove the bolt.

Remove the hoist from the bracket.

Remove the spare tire hoist shaft guide from the bumper.

Install the spare tire hoist shaft guide to the bumper.

Install the hoist to the crossmember.

Install the bolt.

Tighten

Tighten the bolt to 40 N·m (30 lb ft).

 

Install the collar to the hoist.

Install the shaft to the hoist.

Install the spare tire to the hoist.

Rotate the hoist shaft clockwise until the spare tire is in position and the hoist clicks two times or it skips twice. You cannot overtighten the cable.

Remove the safety stands.

Lower the vehicle.

Install the spare tire stowage lock cylinder.

Module Reprogramming

Important: The following vehicles with factory 20" wheels/tires do not require any module reprogramming to upsize to 22" wheels/tires:

• 2008 Chevrolet Avalanche

• 2008 Chevrolet Suburban

• 2008 Chevrolet Tahoe

• 2008 GMC Yukon

• 2008 GMC Yukon XL

 

For proper vehicle operation and to ensure coverage under the provisions of the new vehicle warranty, the vehicle must be reprogrammed with the correct calibrations as soon as the accessory wheels are installed.

 

Contact Techline (1-800-828-6860 English or 1-800-503-3222 French) to obtain a VCI number. Use the Service Programming System (SPS).

 

Important: Module reprogramming must be done using Pass-Thru method.

 

Engine Control Module (ECM)

It will be necessary to reprogram the ECM for speedometer accuracy. Use the following steps:

 

Connect Tech 2® to vehicle and to TIS terminal.

Power ON the Tech 2®.

Turn ON the ignition, with the engine OFF.

Select the proper reprogramming method: "Pass-Thru" and "Reprogram ECU", then "Next."

Build the vehicle.

Verify VIN is correct, then "Next."

Select the proper controller to be programmed: "ECM Engine Control Module."

Select the proper programming mode: "VCI", then "Next."

Enter the VCI number obtained when calling TCSC, then "OK."

On the following Calibration Selection screen, the speedometer calibration has now been added to the calibration set and the box is checked. If a box is not checked, you will have to make the appropriate calibration selection. All boxes must have check marks before going to the next step. Select "Next."

Once the reprogramming is complete, depending on the vehicle build you may be required to perform a Crankshaft Position Variation Learn procedure. Refer to the Checking and Clearing DTCs After Reprogramming procedure listed below.

Electronic Brake Control Module (EBCM)

Important: 2007-2008 GMC Yukon Denali and Denali XL upsizing from factory 20" to accessory 22" are excluded from EBCM reprogramming.

 

With the Tech 2® still connected, select the proper reprogramming method: "Pass-Thru" and "Reprogram ECU", then "Next.".

Build the vehicle.

Verify VIN is correct, then "Next."

Select the proper controller to be programmed: "EBCM Electronic Brake Control Module."

Select the proper programming mode: "Normal" , then "Next."

On the following screen, select the proper calibration "Electronic Brake."

From the part numbers displayed, select the one containing the correct wheel size in its description, "Next."

On the following screen, select "Done."

Checking and Clearing DTCs After Reprogramming

DTCs codes may be set as a result of the programming process. In most cases the codes can be cleared using the Tech 2® and following the procedure listed below.

 

If required, perform the CKP System Variation Learn Procedure (SI Document ID # 1657049).

 

Install the Tech 2® to the vehicle.

Turn ignition ON with engine OFF.

Enter "Diagnostics" and build vehicle according to model year, vehicle line, etc.

Select "Vehicle Control Systems."

Select correct engine.

Select "Vehicle DTC Information."

Select "DTC Display." Scan tool will check all modules for any DTCs that are set.

Select "View all DTCs."

Select "Clear all DTCs."

Press the "exit" key to escape.

Calibration Information Documentation

Make a copy of the "Accessory Wheel and Tire Information Form" included in this bulletin.

Provide all information required on the form.

Make a copy of the completed form for the customer to keep in the vehicle along with their Owner's Manual.

File the original completed form in the Dealership's Vehicle Service History folder.

Important: If original equipment tires/wheels are reinstalled, it will be necessary to reset the programming of the PCM to the original specifications.

 

Warranty Information

Wheels

All GM Accessories sold and permanently installed on a GM vehicle PRIOR to new vehicle delivery will be covered under the provisions of the New Vehicle Limited Warranty.

 

For the U.S., in the event GM Accessories are installed AFTER new vehicle delivery, or are replaced under the new vehicle warranty, they will be covered (parts and labor) for the balance of the vehicle warranty, but in no event less than 12 months/12,000 miles. This coverage is only effective for GM Accessories permanently installed by a GM dealer or a GM approved ADI (Accessory Distributor / Installer).

 

For Canada, in the event GM Accessories are installed AFTER new vehicle delivery, they will be covered (parts and labor) for the balance of the vehicle warranty, or up to 12 months/unlimited kilometers depending on month installed. For replacement after the new vehicle warranty expires, but within the 12 months/unlimited kilometers coverage, refer to claim type "B" guidelines.

 

GM Accessories sold over-the-counter, or those not requiring installation, will continue to receive the standard GM Dealer Parts Warranty of 12 months from the date of purchase (parts only).

 

Tires

Any approved tire installed on a GM Vehicle PRIOR to delivery will be covered under the provisions of the New Vehicle Limited Warranty. Tires are covered against defects in material and workmanship. Tires are warranted for defects "without" prorated charge for tread mileage. Subsequent replacements under this warranty will continue to be covered for the remainder of the New Vehicle Limited Warranty.

 

Any approved tire installed on a GM Vehicle PRIOR to delivery may continue to be warranted on a prorated basis by the tire manufacturer once the New Vehicle Limited Warranty expires.

 

Any approved tire installed AFTER delivery will be covered under the provisions of the tire manufacturer warranty.

 

USA dealers should refer to GM Warranty Administration Bulletin 00-03-10-003I and GM Parts Process / Policy Bulletin IB03-001 for more information.

 

Canadian dealers should refer to GM Warranty Administration Bulletin 01-03-10-003B.

 

GM Warranty Claims Processing

Only GM dealerships have the ability to file warranty claims for GM Parts and Accessories. Therefore, any warranty claims filed against such parts must be handled by the servicing GM dealership. This includes those parts purchased from a GM-approved ADI (Accessory Distributor / Installer).

 

ACCESSORY WHEEL AND TIRE INFORMATION FORM

You have just modified your vehicle by installing an "Accessory Package" which includes Wheels and Tires. This form contains important information about your accessory installation. In an effort to provide superior service to you, our customer, we ask that you please present this form to your Servicing Dealer when removing or installing wheels and tires on your vehicle. This form contains important information necessary to service your vehicle.

 

VIN: __________________________________________________________

 

Original Equipment:

 

VCI #: ____________________________________

 

Tire & Wheel Size: _______________________________________________

 

Accessory Equipment:

 

VCI #: _________________________________________

 

Tire & Wheel Size: _______________________________________________

 

Important: Please store this form in the vehicle with your Owner's Manual. A record of this form will also be kept on file at your Servicing Dealer.

 

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

 

© Copyright General Motors Corporation. All Rights Reserved.

--------------------------------------------------------------------------------

Document ID#

 

AND

 

 

Document ID# 2004650

--------------------------------------------------------------------------------

Subject: Performance Characteristics of Vehicles with Accessory Wheel/Tire Assemblies Installed as Upsized to Original Equipment #05-03-10-005C - (08/21/2007)

 

Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn)

2006-2008 HUMMER H3

--------------------------------------------------------------------------------

 

This bulletin is being revised to add the 2008 model year and include Turning Information for Classic Fullsize Truck and Utility vehicles only. Please discard Corporate Bulletin Number 05-03-10-005B (Section 03 -- Suspension).

--------------------------------------------------------------------------------

When GM Accessories wheel/tire assemblies are installed on a vehicle, customers may notice a change in the driving characteristics of the vehicle. The purpose of this document is to review the different performance characteristics of a vehicle with accessory wheel/tire assemblies installed.

 

Vehicle Performance:

Use of larger "upsized" tire/wheel assemblies, in lieu of the standard factory installed tire/wheel assemblies, can change the vehicle's overall performance characteristics. Depending on road surface and driving conditions, the driver may note changes or differences in the following:

 

• Tire/road noise

• Ride stiffness

• Tire tread wear rate

• Steering effort

• Fuel economy

• Braking performance

• Tire traction (wet/dry/snow/ice)

 

Also, generally, tire chains cannot be used due to lack of clearance to the wheelhouse. Trucks equipped with accessory wheel/tire assemblies will not be compatible for use with snowplow equipment.

 

Turning Information:

Important: This section ONLY applies to the following vehicles:

• 1999-2007 Silverado and Sierra (Classic)

• 2000-2006 Fullsize Utilities

 

In a reverse turn, the tire may contact the plastic inner liner toward the rear and may also contact the sway bar. In a bounce/jounce condition, the tire may contact the top of the wheel house (the metal part inside the fender lip). These are all considered friendly surface contacts, meaning they will not damage the tire/wheel and are a characteristic of the upgrade.

 

Warranty Information

All GM accessories sold and permanently installed on a GM vehicle prior to delivery will be covered under the provisions of the New Vehicle Limited Warranty.

 

The changes in ride handling listed above are considered normal conditions when upgrading to larger wheels/tires and are not covered by the New Vehicle Limited Warranty.

 

Wheels:

For the U.S., in the event GM Accessories are installed AFTER new vehicle delivery, or are replaced under the new vehicle warranty, they will be covered (parts and labor) for the balance of the vehicle warranty, but in no event less than 12 months/12,000 miles. This coverage is only effective for GM Accessories permanently installed by a GM dealer or a GM approved ADI (Accessory Distributor / Installer).

 

For Canada, in the event GM Accessories are installed AFTER new vehicle delivery, they will be covered (parts and labor) for the balance of the vehicle warranty, or up to 12 months/unlimited kilometers depending on month installed. For replacement after the new vehicle warranty expires, but within the 12 months/unlimited kilometers coverage, refer to claim type "B" guidelines.

 

GM Accessories sold over-the-counter, or those not requiring installation, will continue to receive the standard GM Dealer Parts Warranty of 12 months from the date of purchase (parts only).

 

Tires:

Any approved tire installed on a GM Vehicle PRIOR to delivery will be covered under the provisions of the New Vehicle Limited Warranty. Tires are covered against defects in material and workmanship. Tires are warranted for defects "without" prorated charge for tread mileage. Subsequent replacements under this warranty will continue to be covered for the remainder of the New Vehicle Limited Warranty.

 

Any approved tire installed on a GM Vehicle PRIOR to delivery, may continue to be warranted on a prorated basis by the tire manufacturer once the New Vehicle Limited Warranty expires.

 

Any approved tire installed AFTER delivery will be covered under the provisions of the tire manufacturer warranty.

 

U.S. dealers should refer to GM Warranty Administration Bulletin 00-03-10-003K and GM Parts Process/Policy Bulletin 1B03-001 for more information.

 

Canadian dealers should refer to GM Warranty Administration Bulletin 01-03-10-003D.

 

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

 

© Copyright General Motors Corporation. All Rights Reserved.

--------------------------------------------------------------------------------

Document ID# 2004650

Archived

This topic is now archived and is closed to further replies.

  • Latest Articles

  • Posts

    • I am having similar issues.. 08, 4.8L granted I did had a fender bender and minor damage up front passenger side but I don’t think it had anything to do with it.. I had the high and low pressure checked and my fan for my radiator keeps coming on.. replaced the pressure switch and don’t want to keep throwing parts at it. I did have some minor problems here and there like on long road trips sometimes the ac would get a little warm and then on the highway as soon as I give it a little gas or get a little heavier on the petal it started running cooler. Never had an issue with the ac besides the here and there.. but I also started having issues when I fuel up now it takes a bit to start ( super embarrassing) it runs fine and once started ( only happens after fueling up) starts fine any other time. Could they be related?
    • Spent a small fortune on fuel this weekend.   $6.69 diesel, 18 gallons of that. $6.99 92-octane ethanol free, 10 gallons of that for yard machines $5.59 87-octane for one of the cars, 11 gallons.   $250+ and I didn't even get a tug.   Hormuz ain't Hormuzin again, did not see that coming...LOL
    • Appreciate the advice. I've watched multiple videos. Most showing the most complex for those that have a center console, to one that showed maybe 2 pieces of trim being removed, like 6 screws, pulling back the screen and switch assembly, and installing the inline module. And this was a new/newer Silverado. That didn't look too bad. All the others show alot of trim pieces that need to be removed. I've broken those kind of tabs/clips on my C8 Corvette trying to get to the battery, and that was a lot less clips than what I think is involved here after watching multiple videos and looking at my dash today. I have one on the way. Called a reputable stereo place about installing it and got a "minimum" price of $175. Ouch! Looking forward to seeing what the instructions have to say.
    • Hard to say what the issue might be. Anything from the ability to cool the AC condenser up front, to blend door issues in the HVAC unit, to refrigerant charge, to compressor issues or issues in the lines.   Report back what the techs find on the 29th.   GM has service publications which list acceptable vent temperatures and AC pressures at given ambient temps and humidity. They probably won't touch the system if it's operating within those ranges.   I'm also surprised to hear your 2024 with the L8T is still using R134a? I was pretty sure the HD's had switched to the new refrigerant around 2020.
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...