If there is incorrect or incomplete contact of the engine control module's ground line, the engine will not function correctly. Therefore, checking before further diagnosis can save a lot of aggravating time.
See Figure 1
With the ECM connector unplugged, check for continuity of the ground circuit. Connect terminals 101 and 106 to a grounded ohmmeter. There should be continuity between these terminals and the ground, if there is not, the circuit (harness) needs to be repaired or replaced from terminals 101 and 106 to ground.
REMOVAL & INSTALLATION
See Figure 2
Although this particular circuit cannot be removed on its own, the ECM can be removed from the vehicle for easier testing. If any repairs need to be done for this procedure, however, the repairs will be in the harness and not the ECM. The ECM is located under the dashboard on the far right-hand side of the vehicle. It is attached with either 2 or 4 screws, so make sure all screws have been removed before trying to do so, and a harness connector.