2002 Tahoe rear A/C

[gfunk100]

The rear A/C suddenly does not work. The front is operating very well. The heater portion works both in front and in the rear. any suggestions?

[MustGoFaster]

the rear might have a separate resivoir?

or the whole system might be low, the bias might just be to the front since it's so much closer to the compressor. that's just a guess. have it checked, or get one of those neat kits with a guage and check it out.

[03TRAILEXT]

Document ID# 1337786

2003 Chevrolet TrailBlazer - 4WD

 

 

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Air Conditioning (A/C) Inoperative/Intermittent, A/C Blows Warm Air (Replace A/C Low Pressure Cycling Switch) #03-01-39-007 - (May 29, 2003)

Air Conditioning (A/C) Inoperative/Intermittent, A/C Blows Warm Air (Replace A/C Low Pressure Cycling Switch)

2003 Cadillac Escalade, Escalade EXT, Escalade ESV

 

2002-2003 Chevrolet TrailBlazer, TrailBlazer EXT

 

2003 Chevrolet Avalanche, Silverado, Suburban, Tahoe

 

2002-2003 GMC Envoy, Envoy XL

 

2003 GMC Sierra, Yukon, Yukon XL

 

2002-2003 Oldsmobile Bravada

 

2003 HUMMER H2

 

Condition

Some customers may comment that the A/C system is intermittently inoperative or blows warm air.

 

Cause

An intermittent inoperative (open) A/C low pressure cycling switch may be the cause. This is an intermittent condition and temperatures may play a critical role if the vehicle is in the failed mode or operating as designed.

 

Correction

Follow the diagnosis and service procedure below to correct this condition.

 

Park the vehicle inside or in the shade.

Open the windows in order to ventilate the interior of the vehicle.

If the A/C system was operating, allow the A/C system to equalize.

Turn OFF the ignition.

Open the hood and install fender covers.

 

Caution

Avoid breathing the A/C Refrigerant 134a (R-134a) and the lubricant vapor or the mist. Exposure may irritate the eyes, nose, and throat. Work in a well ventilated area. In order to remove R-134a from the A/C system, use service equipment that is certified to meet the requirements of SAE J 2210 (R-134a recycling equipment). If an accidental system discharge occurs, ventilate the work area before continuing service. Additional health and safety information may be obtained from the refrigerant and lubricant manufacturers.

For personal protection, goggles and gloves should be worn and a clean cloth wrapped around fittings, valves, and connections when doing work that includes opening the refrigerant system. If R-134a comes in contact with any part of the body severe frostbite and personal injury can result. The exposed area should be flushed immediately with cold water and prompt medical help should be obtained.

 

 

Notice

R-134a is the only approved refrigerant for use in this vehicle. The use of any other refrigerant may result in poor system performance or component failure.

To avoid system damage use only R-134a dedicated tools when servicing the A/C system.

Use only Polyalkylene Glycol Synthetic Refrigerant Oil (PAG) for internal circulation through the R-134a A/C system and only 525 viscosity mineral oil on fitting threads and O-rings. If lubricants other than those specified are used, compressor failure and/or fitting seizure may result.

R-12 refrigerant and R-134a refrigerant must never be mixed, even in the smallest of amounts, as they are incompatible with each other. If the refrigerants are mixed, compressor failure is likely to occur. Refer to the manufacturer instructions included with the service equipment before servicing.

 

Install the J 43600 ACR 2000 Air Conditioning Service Center.

 

Important

The ambient temperature must be at least 16°C (60°F) .

Do not induce additional air flow across the front of the vehicle during the test.

 

Record the ambient temperature displayed on the J 43600.

Record readings of the low and high side STATIC pressures. The pressures should be within the specifications listed below.

Above 16°C (60°F): 345 kPa (50 psi)

Above 24°C (75°F): 483 kPa (70 psi)

Above 33°C (90°F): 690 kPa (100 psi)

If the static pressures are within specification, continue with Step 12.

If the static pressures are NOT within specifications, refer to Leak Testing (SI Document ID# 1141201).

Apply the parking brake.

Place the transaxle/transmission in PARK.

Start the engine.

Turn on the A/C system.

Inspect the A/C compressor to see if it is operating properly.

 

 

 

If the compressor is not operating as designed, tap on the low pressure cycling switch (2) with a small hand tool. The compressor should start operating correctly.

If the compressor does not operate correctly after tapping on the low pressure cycling switch (2), disconnect the switch and jumper the lower pressure cycling switch connector with a fused jumper. If the compressor still does not operate properly, refer to HVAC Compressor Clutch Does Not Engage diagnostic in SI.

 

Important

DO NOT USE A/C low pressure cycling switch, P/N 15035084 on the vehicles listed above.

 

 

If the compressor does operate correctly after tapping on the switch or jumping the low pressure cycling switch connector, replace the low pressure cycling switch (2), P/N 89040362. Refer to Air Conditioning (A/C) Low Pressure Switch Replacement in SI.

Perform the Air Conditioning (A/C) System Performance Test in SI.

Disconnect the J 43600 ACR 2000 Air Conditioning Service Center.

Remove the fender covers and close the hood.

Parts Information

 

Important

Only a small quantity of parts are available. Please DO NOT order for stock only.

 

 

Part Number

Description

Qty

 

89040362

Switch, Pressure Cycling

1

 

 

Parts are currently available from GMSPO.

 

Warranty Information

Labor Operation

Description

Labor Time

 

D1180

Switch, Pressure Cycling - Replace

Use published labor operation time

 

Add

Diagnosis Time

0.0-0.3 hr

[03TRAILEXT]

Document ID# 976592

2003 Chevrolet TrailBlazer - 4WD

 

 

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HVAC System Inoperative for a Drive Cycle, Poor HVAC System Performance in High Ambient Temperatures (Update HVAC Control Module Software) #02-01-39-005 - (Sep 23, 2002)

HVAC System Inoperative For A Drive Cycle, Poor HVAC System Performance In High Ambient Temperatures (Update HVAC Control Module Software)

2002-2003 Chevrolet TrailBlazer, TrailBlazer EXT

 

2002-2003 GMC Envoy, Envoy XL

 

2002-2003 Oldsmobile Bravada

 

Condition

Some customers may comment about no cold air from the heating, ventilation and air conditioning (HVAC) system during a drive cycle. This concern may occur at any time during the drive cycle and at any temperature setting. The HVAC system operation returns to normal after the vehicle has been keyed to off and restarted. This concern is intermittent and most likely to occur on hot days. This concern may be found on vehicles equipped with manual (CJ2) and automatic (CJ3) HVAC systems. Other customers may comment about poor HVAC system performance in high ambient temperature conditions. This concern may be present in automatic (CJ2) HVAC systems only. An HVAC control module software update was put into all production vehicles beginning in September 2002. Vehicles built in September 2002 and earlier may need this software update.

 

Correction

Update the HVAC control module using software available through GM Access beginning September 9, 2002. The update will be fully available October 7, 2002 to all dealers on TIS 2000 CD version 10. This software update addresses both the intermittent no cooling and the poor performance concerns. If the software update does not correct the concerns, perform the HVAC Diagnostic System Check and repair as necessary. If the HVAC control module is replaced with a part from GMSPO, make sure the module has the latest software update. The module may need to be updated even though it is a new part.

 

Warranty Information

For vehicles repaired under warranty, use:

 

Labor Operation

Description

Labor Time

 

D4707

Module or Assembly, HVAC Control Head - Reprogram

0.4 hr

[consejero]

The rear A/C suddenly does not work. The front is operating very well. The heater portion works both in front and in the rear. any suggestions?

 

 

Same problem! Please oh please someone email me with a fix.... I'm pulling what's left of my hair out !!!

[email protected]

 

Front works great with new compressor, Rear nothing.

[Fortune50]

If the blower is working ok, then look to either an a/c refrigerant pressure issue (low charge), weak compressor, contaminated refrigerant, blockage of flow in the refrigerant system, or a rear hvac controller or actuator problem.

Check the static (engine OFF) pressure of the a/c's high & low ports, should be around 70 psi at 75* (outside temp), to 100 psi @ 90*. If they read low, then the a/c system has a leak and it will need to be fixed and then re-charged.

If the static pressure seems ok, then I'd look for a temp actuator door problem. You have to remove the rear quarter interior trim panel to access the rear hvac. See if the temp actuator's "drive shaft" moves when turning the temp control from hot to cold. If it moves, but still warm air comes out, there could be either a mechanical problem w/ the actuator door, or the a/c system has a problem w/ refrigerant flow other than a low charge. If it doesn't move, then you'll have to then check for power at the black/white wire at the actuator's harness. Also be sure the black wire has good continuity to ground. If both check out ok, then the actuator may have failed. If no power getting to the actuator, then there may be a problem w/ the controller for the rear hvac. Hope this helps, good luck and keep us updated if you get it fixed.

EDIT: forgot to mention to check the 10 amp IGN 3 fuse, it's only going to have power w/ the keyswitch to RUN.