Document ID# 671751
2001 Chevrolet Corvette


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DTC P0327 or P0332
Circuit Description
The knock sensors (KS) produce an AC signal under all engine operating conditions. The powertrain control module (PCM) calculates the average voltage range of each KS signal. If the KS system is operating correctly, the PCM will monitor the KS voltage which is varying above and below an average voltage. If the PCM detects a KS 1 signal, or a KS 2 signal voltage, within an average voltage range, a DTC will be set. DTC P0327 refers to the front KS. DTC P0332 refers to the rear KS.

Conditions for Running the DTC
• DTCs P0117, P0118, P0125, P1114, P1115, P1120, or P1121 are not set.

• The engine speed is between 1,650-3,000 RPM.

• The manifold absolute pressure (MAP) is less than 49 kPa (7.1 psi).

• The engine coolant temperature (ECT) is more than 60°C (140°F).

• The throttle angle is more than 0 percent.

• The engine has been operating for more than 10 seconds.

• The ignition voltage is more than 10 seconds.

Conditions for Setting the DTC
The PCM determines that this frequency is less than the expected amount for more than 9 seconds.

Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
• The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

• Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
• Inspect the knock sensor for proper installation. A loose knock sensor or overtightened knock sensor may cause the DTC set.

• For an intermittent condition, refer to Intermittent Conditions .

Test Description
The numbers below refer to the step numbers on the diagnostic table.

This verifies that the malfunction is present.

This step simulates an engine knock.

Step
Action
Values
Yes
No

Schematic Reference: Engine Controls Schematics

1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls

2
Important: Before proceeding with this diagnostic test, listen for an engine knock. If you hear an engine knock, repair the engine mechanical condition.


Turn ON the ignition, with the engine OFF.
Review the Freeze Frame/Failure Records for this DTC, and observe the parameters.
Turn OFF the ignition for 30 seconds.
Start the engine.
In order to set the DTC, operate the vehicle within the following parameters:
- Conditions for Running the DTC

- Conditions that duplicate the data which are found in the Freeze Frame and in the Failure Records

Does the scan tool indicate that this diagnostic test failed this ignition?
--
Go to Step 3
Go to Diagnostic Aids

3
Remove the left engine sight shield.
Disconnect the KS jumper harness connector that is located on the left side of the intake manifold.
Set the DMM to the 400K ohm scale.
Measure the resistance of the appropriate KS by connecting the DMM between a good ground and the knock sensor jumper harness connector.
Is the resistance of the KS within the specified range?
93-107Kohms
Go to Step 4
Go to Step 6

4
Leave the DMM connected.
Set the DMM to the 400 mV hertz voltage scale. Refer to Splicing Twisted or Shielded Cable in Wiring Systems.
Important: Do not tap the plastic engine components.


Tap the engine in the area of the appropriate KS while you observe the signal that is indicated on the DMM .
Is any signal indicated on the DMM while you tapped on the engine block near the KS?
--
Go to Step 5
Go to Step 7

5
Disconnect the PCM connector. Refer to Powertrain Control Module (PCM) Replacement .
Test the KS signal circuit between the PCM and the knock sensor connector for the following conditions:
- An open

- A short to voltage

- A short to ground

Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 9

6
Remove the intake manifold. Refer to Intake Manifold Replacement in Engine Mechanical-5.7L.
Test for an open or for a short to ground in the signal circuit between the KS jumper harness connector and the KS harness connector. Refer to Testing for Continuity or to Testing for Short to Ground in Wiring Systems.
Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 7

7
Inspect the KS signal circuit for a poor connection at the appropriate KS. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
If you find a poor connection, repair the connector as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 8

8
Replace the KS. Refer to Knock Sensor (KS) Replacement .

Did you complete the replacement?
--
Go to Step 12
--

9
Inspect the KS signal circuit for a poor connection at the KS jumper harness connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
If you find a poor connection, repair the connector as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 10

10
Inspect the KS signal circuit for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
If you find a poor connection, repair the connector as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 11

11
Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .

Is the action complete?
--
Go to Step 12
--

12
Use a scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC.
Does the DTC run and pass?
--
Go to Step 13
Go to Step 2

13
With a scan tool, observe the Stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK



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Document ID# 671751
2001 Chevrolet Corvette

Document ID# 893793
2001 Chevrolet Corvette


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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)
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).

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.