P131

Circuit Description

This test checks the Knock Sensor ability to detect a knock. This is accomplished by the PCM adding increasing levels of spark that should cause detonation and seeing if the Knock Sensor detects knock. If no knock is detected Code P131 will set. If knock is detected, the test is considered passed and normal spark control will resume.

Test Condition(s)

1. MAP value not varying by more than 10 kPa at steady state operation.
2. IAT value greater than 30°C.
3. Coolant temperature 40°C or greater.
4. Battery voltage 11 or greater volts.
5. Engine rpm:

a. 1200 < rpm < or equal to 1255
OR
b. 3600 < rpm < or equal to 5100

6. Engine running for at least 2 seconds.

Failure Condition(s)

The ramp spark value of 30 will be incremented until a maximum of 210 is reached. If no knock is detected for 1 second at maximum spark Code P131 will set.

Action Taken

None.

Notes on Fault Tree

1. Check if Code P132 is also set because a circuitry problem can cause a sensor problem.
2. Checking the knock sensor ability to detect an induced knock.