Where are the knock sensors on a 6.0l?

Roach182 · December 22, 2006

First off let me say thank you to the fine folks on this board. I browsed this board yesterday looking for info on trouble codes on a recently purchased 2003 silverado 2500HD 6.0l . I don't have the paper with me I wrote the codes on but I beleive they were p0332 and p0327. Never the less there is code that consistantly comes in on one knock sensor bank and the other bank is intermittant. The truck is underpowered and is running lean (very white plugs) and the OBD II shows intermittant misfires on all cylinders. From readind many threads on this forum I discovered that it was well worth checking out the wiring too the knock sensors. I found two wires in a harness that goes from a plug under the shroud on top of the engine then underneath the intake manifold at the rear of the motor. This connector was full of water, I dried it out and cleaned the contacts. Is it one of my knock sensors? And if so where would the other one be so I can check the wires on it? Also will this engine code clear itself when the problem is repaired or do I have to reset it with the OBD? Thanks in advance.

Gowan

Norseman · December 22, 2006

The sensors (there are 2) are under the intake. There is a TSB about water intrusion in the rear sensor. Here is the text to the TSB

***NOTE***

If you do decide to replace your knock sensors MAKE SURE YOU USE THE UPDATED REPLACEMENT GASKETS FOR THE INTAKE MANIFOLD. The updated replacement gaskets GM part number 89017589 are teal green in color. DO NOT REUSE THE OLD GASKET.

Subject: Audible Spark Knock (Detonation), MIL Illuminated, DTC P0332 Set (Replace Rear Bank Knock Sensor and RTV Area Around Sensor)

Models: 1998-2002 Chevrolet Camaro, Corvette

1998-2002 Pontiac Firebird

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

1999-2003 Chevrolet Silverado, Suburban, Tahoe

2002-2003 Chevrolet Avalance

1999-2003 GMC Sierra, Yukon, Yukon XL

2002-2003 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

Roach182 · December 22, 2006

Thanks Norseman, I was aware of the TSB from reading other threads on this bulliten board, but I wonder if my condition is alittle different. On the OBD I am getting P0327(Knock Senor 1 - Circuit Low Input Bank 1) intermitantly as well as P0332(Knock Sensor 2 - Circuit Low Input Bank 2) intermitantly. I am also getting (Knock Sensor 2 - Circuit low frequency) regularly. Will these codes clear on thier own when the trouble is fixed or do they need a manual reset? I found one set of wires going under the intake manifold at the rear of the motor, where is the other set? Or are they wired in series or parallel and there is only one set of wires?

Thanks.