The Engine Control Module (ECM) detects the following conditions:

•A timing calibration has never been performed on a new ECM or the timing is off by more than three degrees.

The speed/timing sensors provide engine speed signals to the ECM. The signals are created as the timing gear on the camshaft rotates past the pickups of the engine speed/timing sensors. A unique pattern on the timing gear allows the ECM to determine the crankshaft position. This unique pattern on the gear allows the ECM to determine the top center position of the piston in the No. 1 cylinder. If the signal is lost from one of the sensors, a diagnostic code is generated. The ECM will use a special type of logic that will allow the engine to start on only one sensor.

Timing calibration is accomplished by installing a special magnetic pickup into the side of the engine block. The magnetic pickup senses a special slot on the crankshaft counterweight.

Note: The timing calibration will not increase the available engine power. Do not expect an increase in power due to the performance of the timing calibration.

You can only calibrate this using the CAT ET Software.