Diagnostic Aids
- An open or a short in the serial data circuits of the theft deterrent control module can cause a DTC P1626 to set. The serial data circuit fault will also cause the following conditions:
- The theft deterrent status will switch to Enable and the engine will crank but not start.
- If there is open circuit, the scan tool will not communicate with the ECM, but will continue to communicate with the transmission control module (TCM).
- If there is a short circuit, the scan tool will not communicate with either the ECM or the TCM.
- The DTC P1626 will be stored in memory and is displayed by the scan tool when communication with the ECM resumes.
- An intermittent electrical condition in the theft deterrent system can cause this code to set. Refer to Testing for Intermittent Conditions and Poor Connections .