Component Tests and General Diagnostics

NEW PCM - SAME PROBLEMS
If the Powertrain Control Module (PCM) is replaced but does not correct the problem, one of the following may be the reason:

Terminal Connections
There is a problem with the PCM terminal connections. The diagnostic chart will say PCM connections or PCM. The terminals may have to be removed from the connector in order to check them properly.

Intermittents
The problem is intermittent. - This means that the problem is not present at the time the system is being checked. In this case, refer to the Diagnosis By Symptom and make a careful physical inspection of all applicable systems involved. Testing and Inspection

Electrical Shorts
Shorted solenoid, relay coil, or harness. Solenoids and relays are turned "ON" and "OFF" by the PCM using internal electronic switches called "drivers."

A shorted solenoid, relay coil, or PCM harness will not damage the PCM but will cause the component to be inoperative.

TEST TOOLS
J 34636 or BT-8405 testers or equivalent provide a fast, accurate means of checking for a shorted coil or a short to battery voltage.