P131

DTC P131:

Knock Sensor Circuit:

CIRCUIT DESCRIPTION
This test checks the Knock Sensor's ability to detect a knock. This is accomplished by the Powertrain Control Module (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 CONDITIONS
1. Manifold Absolute Pressure (MAP) value not varying by more than 10 kPa at steady state operation.
2. Intake Air Temperature (IAT) value greater than 30°C.
3. Coolant temperature 40°C or greater.
4. Battery voltage 11 volts or greater.
5. Engine rpm:

a. RPM greater than 1200 but less than or equal to 1225
OR
b. RPM greater than 3000 but less than or equal to 6375 (3.11 final drive, VIN Y)
rpm greater than 3600 but less than or equal to 5100 (3.71 final drive, VIN 9)

6. Engine running for at least 2 seconds.

FAILURE CONDITION
The ramp spark value of 0.3° for 3.11 final drive (VIN Y) or 3° for 3.71 final drive (VIN 9) will be incremented until a maximum of 21° 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's ability to detect an induced knock.