Questions and Answers

Saturn SL1 DTC P0341 Q. I have a 1997 Saturn SL1 with 1.9 liter SOHC, about 124,000 miles, fuel injected and automatic transmission. It's not a very happy car, but I know most of what it needs. I just brought it in to have the engine codes read. P0405 and P1404 seem well documented, and easily researched.

My problem is P0341 Camshaft Position Sensor Circuit Range/Performance. Is this electrical or mechanical? What can I do about it?

Thanks and great site.

A. The electronic ignition (EI) module supplies a signal to the PCM whenever it determines that #4 cylinder fired on its compression stroke. Because of opposite coil tower polarity, the simultaneous fire of #1 and #4 cylinders are of opposite polarity as well.

Under most conditions (except decel), the waste spark cylinder fires before the compression cylinder in sequence. The EI module can determine this polarity sequence and voltage amplitude by using capacitive pickup plates located under the 1/4 coil.

If the module senses a positive to negative sequence and high negative spike when #4 is on TDC, it pulls the PCM cam signal to ground signaling that #4 has just fired on compression. This signal along with the double pulse received from the CKP sensor, synchronizes spark and fuel timing.

Only one #4 signal should be received every 14 crank pulses. DTC P0341 will set if the cam signal received by the PCM is incorrect or has too many pulses per crankshaft revolution when:

• The engine has been cranking for 5-10 seconds.

OR

• The engine is running.

NOTE: The cam signal is continuously checked when crankshaft sensor pulses are received by the PCM, except under deceleration.

DIAGNOSTIC AIDS
When attempting to diagnose an intermittent problem use the Scan tool to review malfunction history diagnostic information. The supplemental data can be used to duplicate a problem.

Intermittents or opens suspected to be at the connector can be detected by using diagnostic service probe. Voltage can be read on wire without disconnecting any connectors.

Check the tightness of the female terminal grip with a spare male terminal.

NOTE: Too many cam pulses may not affect engine operation.

• If an open circuit exists on #4 cylinder a DTC P0341 may set. This is due to the polarity and amplitude of the coil during every firing event cooling as if #4 cylinder is on compression. The PCM thinks #4 cylinder is on compression every crankshaft revolution. Refer to misfire diagnostics if the engine has a misfire. High resistance in the plug wire and connections, or plug will cause P0341.