Connectors for Knock Sensors

[Trucked-up]

I have a 99 GMC Sierra ECSB with a LS1 from a 99 TA. I have been logging my knock retard with EASE diagnostics and am getting a consistant 8* of knock. I have read that 99 trucks are notorious for this problem.

I put 5 gallons of 100 octane gas in and logged again, still 8* of knock. Based on this I believe I am getting "false" knock. I would like to de-sensitize my knock sensors. I have read on other forums about putting a 10K ohm resistor in line with each sensor. The knock sensor harness that goes from the back of the intake to the pcm is where I would like to install the resistors. I would like to make a short section to install these resistors in line so that I can un-plug them when I want to.

Does anyone know the GM part number for the 2 connectors I will need.

Has anyone on this site performed this mod and if so what resistor values did you use?

Thanks for the help.

Tony

[Bandit]

Not exactly what you described but see if this helps:

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

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

ConditionSome 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.

CauseThis 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.

CorrectionReplace 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. TightenTighten 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 InformationPart Number

Description

Qty


10456603

Sensor, Knock

1


Parts are currently available from GMSPO.


I have seen and repaired a few of these. Another thing to do is get on http://calid.gm.com and see if there is a flash update available to rectify the problem.


Bandit!

[BigKID]

I have done exactly what you described and it works great. I dont know the pn for the connectors. I just went to the salvage yard and yanked some off a wrecked truck. The same connectors are all over the engine bay. Just make sure you solder the resistors on rather than using but connectors and use some heat shrink to cover them.

[Flyer]

I remember reading somewhere that the knock sensros are engine specific. You may try getting new sensors for that size engine, not necesarilly your truck, but what ever the engine came out of.

The reading said something about the knock sensors are calibrated to pick up knock on a given displacement engine since different displacement will have different 'sounds' and will have a different 'tone' of knock.