Engine Controls - MIL ON/DTC P0332/Spark Knock
TECHNICALBulletin No.: 08-06-04-030A
Date: January 29, 2010
Subject: Malfunction Indicator Lamp (MIL), Intermittent Check Engine Light On, Engine Spark Knock/Ping (Detonation), DTC P0332 Set (Diagnose and Repair as Necessary)
Models:
2008 Buick Lucerne
with 3.8L V6 Engine (VIN 2 - RPO L26)
Supercede:
This bulletin is being revised to update the correction information. Please discard Corporate Bulletin Number 08-06-04-030 (Section 06 - Engine).
Condition
Some customers may comment on a engine ping noise (commonly referred to as spark knock), usually during acceleration or when the engine is under a load.
Upon investigation, the technician may find DTC P0332 set as current or in history.
If the condition is found to be intermittent, it can be duplicated by performing a brake torque test keeping a constant 2,000 RPM. Do not vary the accelerator pedal. Engine coolant temperature should be more than 60°C (140°F). After more than 30 seconds of engine run time, the DTC should set.
Cause
This condition may be caused by the bank 2 knock sensor inline electrical connector not being fully seated.
Correction
Perform the following circuit/system test and repair as necessary. This procedure is being provided to aid in reduction of unnecessary knock sensor or PCM replacement.
1. Check for a poor connection at the bank 2 knock sensor.
2. Check for good continuity in circuit 1876 between the PCM X2 connector pin 58 and the knock sensor connector. Check for a poor connection at the bank 2 knock sensor inline electrical connector X108. Wiggle both the engine harness side and jumper side of the connector to look for a intermittent connection or a partially broken wire.
3. Ignition OFF, disconnect the knock sensor. While the connector is off, ensure that the sensor is properly tightened. Torque should be 18Nm(13 lb ft).
4. Ignition OFF, measure the resistance from the knock sensor signal terminal to a good ground with a DMM. If the resistance does not measure 100K ohms +/- 7, replace the knock sensor.
Important
DO NOT tap on plastic engine components.
5. Ignition OFF. DMM still connected from previous step, set the DMM to the 400 V AC scale, select the Hz mode. Let the reading stabilize at 0 Hz. Tap on the engine block with a non-metallic object near the sensor while observing the signal indicated on the DMM. If the DMM does not display a fluctuating frequency while tapping on the engine block, then replace the sensor.
6. Ignition OFF, with appropriate length jumper wires, connect the KS1 harness to the KS2 sensor and the KS2 harness to the KS1 sensor. Monitor the DTCs using a scan tool. Operate the vehicle within the conditions for running the DTC. Verify the fault does not follow the sensor in question. If the fault follows the sensor in question, replace the appropriate KS.
7. Ignition OFF, remove the jumper wires from the previous step. Set the DMM to the 400 mV DC scale.
8. Ignition ON, engine OFF. Measure for 4.2 mV - 10.0 mV between the affected KS harness signal terminal and ground.
- If more than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal replace the PCM.
- If less than the specified range, test the signal circuit for an open, short to ground, or high resistance. If the circuit tests normal replace the PCM.
9. Check for intermittent or poor connection at the PCM, KS, and in-line connectors where present.
10. If all circuits test normal, replace the PCM.
Warranty Information
For vehicles repaired under warranty, use the table above.
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