Saab P1391 Fault Code – Causes and Solutions

Meaning of Saab P1391 Code

The P1391 code on a Saab is generally related to a problem with the Camshaft Position Monitor (CMP) system. It may indicate misalignment between the crankshaft and camshaft, or a malfunction of the camshaft position sensor (CMP).

Possible Causes

1. Timing Issue: The timing belt may be misaligned or worn.
2. Faulty CMP Sensor: The camshaft position sensor may be damaged or dirty.
3. Electrical Problem: Damaged wires, corroded connectors, or short circuit.
4. Timing Adjuster Issue (if applicable).
5. Engine Control Unit (ECU) Problem – Rare, but possible.

Diagnosis and Solutions

1. Check the Timing Belt:
   • Inspect alignment and tension.
   • If worn or jumped, replace it.
2. Test the CMP Sensor:
   • Check resistance and signal with a multimeter.
   • Clean or replace the sensor if necessary.
3. Inspect the Wiring:
   • Look for broken wires or corroded connectors.
4. Reset the Fault:
   • Clear the code with an OBD2 tool and see if it returns.
5. Check the ECU:
   • If the problem persists, reprogramming or replacing the ECU may be necessary.

Conclusion

The P1391 code on a Saab is often related to a timing issue or CMP sensor problem. A thorough inspection of the timing system and electrical components is required to resolve the issue.