Circuit/System Testing

WARNING: This page is about a different car, the 2011 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.

P0324

This DTC indicates an internal control module circuitry failure. Replace the engine control module (ECM).

P0325, P0327, P0328, P0330, P0332, and P0333

Ignition ON, engine OFF
Disconnect the Engine Harness to the Engine Jumper Harness at the driver's side of the engine.
Measure for 2-3 V between each of the following circuits and ground on the ECM side of the harness connector.
- Knock sensor bank 1 signal circuit terminal G
- Knock sensor bank 1 signal circuit terminal H
- Knock sensor bank 2 signal circuit terminal J
- Knock sensor bank 2 signal circuit terminal K
- If less than the specified range, test the circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the ECM.
- If greater than the specified range, test the circuits for a short to voltage. If the circuits test normal, replace the ECM.
Test the KS circuits on the KS side of the connector for the following:
- Open/high resistance
- Short to ground
- Short to any other circuit
If all circuits test normal, replace the appropriate KS.

P0326

IMPORTANT:

If DTC P0325, P0327, P0328, P0330, P0332, P0333, P0335, or P0336 are also set, diagnose those DTCs first.

Inspect for a loose or broken vehicle accessory or accessory bracket.
Inspect for excessive engine mechanical noise.