Rear bank knock sensor corrosion from water intrusion (P0332)

Applies toThe bulletin covers 1999-2002 Chevrolet and GMC C/K pickup and utility models, including Yukon, Yukon XL, Yukon Denali and Yukon Denali XL, with the 4.8L, 5.3L or 6.0L engine.

1999-2002 Chevrolet and GMC C/K Pickup and Utility Models (Avalanche, Silverado, Sierra, Tahoe, Suburban, Yukon, Yukon XL, Yukon Denali, Yukon Denali XL) with 4.8L, 5.3L or 6.0L Engine— [1] Models

First signsCustomers may report mild to severe engine ping (spark knock), usually worse during acceleration, and/or an illuminated MIL.

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.— [1] Condition

First signsThe technician may find DTC P0332 set.

Upon investigation, the technician may find DTC P0332 set.— [1] Condition

Why it happensThe condition may result from corrosion of the rear bank knock sensor caused by water intrusion into the sensor cavity.

This condition may be the result of corrosion of the rear bank knock sensor due to water intrusion into the sensor cavity.— [1] Cause

Why it happensIt is more apparent on vehicles whose engine compartment is washed frequently.

This condition is more apparent on vehicles in which customers frequently wash the engine compartment.— [1] Cause

RepairReplace the rear bank knock sensor and build an RTV dam around the sensor to divert water away from it.

Replace the rear bank knock sensor and build a dam (wall) around the sensor using RTV to divert water away from the sensor.— [1] Correction

CautionDo not form the RTV into a complete circle; leave the rear section open.

DO NOT form a complete circle. Leave the rear section open as shown.— [1] Correction

How to confirmIf P0327 and P0332 set at the same time, inspect for poor connections at the two-wire knock sensor harness located at the left rear side of the intake manifold near the top, just under the cover.

if DTCs P0327 and P0332 are set at the same time, inspect for poor connections at the two-wire knock sensor harness, located at the left rear side of the intake manifold near the top, just under the cover.— [2] Known Issue

How to confirmCheck the resistance of the knock sensors including the harness before reinstalling the intake manifold.

Always check resistance of the knock sensors including the harness before reinstalling the intake manifold.— [2] TIP