From GN/Ttype.org:
CODE 41
Trouble Code 41 indicates that the Camshaft Sensor is not functioning properly.
The ignition module uses the Cam Sensor signal for timing the spark firing. The ignition module also passes this signal to the ECM to enable sequential fuel injection. The inability to properly determine engine position from the Cam Sensor will generate Code 41.
The engine will continue to run if the signal is lost from the sensor, however it will not restart after shut down. If the Cam signal from the ignition module to the ECM is lost while running, the ECM will switch to the simultaneous fuel injection mode. The engine can be re-started but will continue to run in the simultaneous mode as long as the fault is present.
The conditions for setting this code are:
the engine is running, and
the Cam Sensor signal is not received by the ECM in the last 1 second interval
Typical causes for this code include:
1) Loose or misadjusted Cam Sensor
2) Defective Cam Sensor-to-ECM connections
3) Defective ECM
Cam sensor installation and adjustment procedures call for very exact tolerances. It is for this reason that it is recommended that the service manual be consulted while performing any adjustment or replacement of the Camshaft Sensor.
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Cam Sensor Adjustment Procedure
1. Measure on a piece of masking tape and mark it at 1.45" and tape it to the Balancer at 0 degrees.
2. Bring #1 to TDC and then grab the intercooler fan and rotate the motor to your mark (25 degrees ATDC). This takes a little patience and muscle. You can try bumping it with the starter, but I'm never very successful at that.
3. Back probe the middle wire of the cam sensor (marked B and normally blue) with a voltmeter. Turn the key ON, but leave the engine OFF.
4. Loosen the sensor with a distributor wrench or a wobble socket and extension.
5. Rotate the sensor full CLOCKWISE. The voltmeter should read 7.5+ volts.
6. Slowly rotate the sensor COUNTER clockwise until the voltage drops.
7. Secure the sensor at the instant the voltage drops.
The sensor is a hall effect device with a rotating metal ring that is driven from the front of the cam gear via a shaft (like a distributor). This ring passes thru a grooved sensor molded into the sensor cap. The metal ring has a notch or window cut out of it. When the window goes by the sensor, the voltage drops, which tells the ECM where #1 TDC is.
HTH - Jimmy
