Service Engine Soon

tmaj1865 · December 10, 2004

I have a 01 HD 6.0 4x4. aboout a month ago my service engine soon light came on, I went to the local parts house to use their code scanner, It read the #2 knock sensor, no big deal I thought because I had some bad gas, and the truck was pinging really bad, so I erased the code with the scanner, and the light went out. Now after about 15 mile the light came back on, so I figured the knock sensor is bad and I will replace it. This is the weird part, The light went out???? at first I thought the bulb burnt out , but its not, Now its been out for 2 days, it came back on this afternoon, I'm really stumped any ideas on what it could be???? Thanks Mike

Haulin' 8.1 · December 11, 2004

It's probably still the knock sensor Mike, many things only turn the light on while they are still broke. Electrical parts like to short in and out before they die all together and that's probably the case.

If you can hear knock the sensor is broken or you're running lamp oil.

Vernon

GM-Tech · December 11, 2004

The knock sensors sit in a well in the area between the cylinder heads and those wells tend to fill with water and the knock sensor connections develop corrosion.

There's a TSB on this problem. Basically, fix the sensors/connections as needed, build a dam in front of the well with RTV and toss away the foam seal at the end of the manifold that tends to trap water in that area.

GM-Tech · December 11, 2004

Here ya go...

Audible Spark Knock (Detonation), MIL Illuminated, DTC P0332 Set (Replace Rear Bank Knock Sensor and RTV Area Around Sensor) #02-06-04-023A - (Jun 14, 2002)

1998-2002 Chevrolet Camaro, Corvette

1998-2002 Pontiac Firebird

with 5.7L Engine (VIN G -- RPO LS1)

1999-2002 Chevrolet Silverado, Suburban, Tahoe

2002 Chevrolet Avalance

1999-2002 GMC Sierra, Yukon, Yukon XL

2002 Cadillac Escalade, Escalade EXT

with 4.8L, 5.3L or 6.0L Engine (VINs V, T, Z, N, U -- RPOs LR4, LM7, L59, LQ9, LQ4)

This bulletin is being revised to add Cadillac Escalade and Cadillac Escalade EXT to the Models. Please discard Corporate Bulletin Number 02-06-04-023 (Section 6 -- Engine/Propulsion System).

Condition

Some customers may comment on a mild to severe engine ping (commonly referred to as spark knock), usually worse during acceleration and/or an illuminated MIL. Upon investigation, the technician may find DTC P0332 set.

Cause

This condition may be the result of corrosion of the rear bank knock sensor due to water intrusion into the sensor cavity. This condition is more apparent on vehicles in which customers frequently wash the engine compartment.

Correction

Replace the rear bank knock sensor and build a dam (wall) around the sensor using RTV to divert water away from the sensor. Use the procedure and part number listed below.

Remove the intake manifold. Refer to the Intake Manifold Replacement procedure in the Engine Controls sub-section of the appropriate Service Manual.

Remove the wiring harness assembly from the knock sensor.

Remove the rear bank knock sensor.

Install the new rear bank knock sensor.

Tighten

Tighten the knock sensor to 20 N·m(15 lb ft).

Install the wiring harness assembly to the knock sensor.

Apply a bead of RTV silicone sealant approximately 9 mm (3/8 in) wide and 6 mm (1/4 in) high along the outside edge of the ridge on the engine block valley cover around the rear bank knock sensor. DO NOT form a complete circle. Leave the rear section open as shown.

From the underside of the intake manifold, completely remove the rear intake manifold seal (foam material).

Install the intake manifold. Refer to the Intake Manifold Replacement procedure in the Engine Controls sub-section of the appropriate Service Manual.

Parts Information

Part Number

Description

Qty

10456603

Sensor, Knock

1

Parts are currently available from GMSPO.

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time

J4437

(F-Car)

Sensor, Knock -- Replace

1.7 hrs

Add

(1998-1999 F-Car Only)

To Remove EGR

0.2 hr

J4437

(Y-Car)

Sensor, Knock -- Replace

1.6 hrs

J4437

(C/K-Truck)

Sensor, Knock -- Replace

1.5 hrs

Add

(C/K Truck Only)

With Three Piece Engine Covers

0.2 hr

Add

(All)

Diagnosis Time

0.3 hr

Add

(All)

To RTV Area Around Sensor and Remove Intake Manifold Seal

0.2 hr

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

tmaj1865 · December 11, 2004

I'm assuming that the knock sensor is under the intake, but is this something I should take to the dealer to fix???? I have no problem tearing it apart to fix it as long as there is no hidden suprises. What would happen if I drive it for a while or do I need to fix right away to stop any further problems??? It would'nt happen until after the first of the year?? . Another thing I heard some bad thing about the Hypertech programer, I notice that after I installed It would ping with regular gas even on the 87 setting, so I have been running super 93 gas on the 87 setting with no ping. Hypertech claims its because of the K&N box to much air lean mix??? Sorry for all the questions but you all seen to know your stuff. Thanks Mike

GM-Tech · December 11, 2004

I'm assuming that the knock sensor is under the intake, but is this something I should take to the dealer to fix???? I have no problem tearing it apart to fix it as long as there is no hidden suprises. What would happen if I drive it for a while or do I need to fix right away to stop any further problems???

No major problems will result if you don't fix it right away, as long as you don't develop a constant detonation that could eat a hole in a piston.

It's not a difficult job at all. I don't see you running into any surprises.