Diagnostic Aids
WARNING: This page is about a different car, the 2002 Mercury Villager. However, it is still accessible from the selected car via links, so may be relevant.
Perform this test when instructed during QUICK TEST or another SYSTEM TEST. This test is used to diagnose the following:
- ISO communication harness circuit.
- GND and B+ harness circuit.
- Faulty PCM.
- Faulty Transmission Control Module (TCM).
PCM-TO-TCM COMM CIRCUIT IDENTIFICATION
| PCM Terminal No. | Circuit | Wire Color | TCM Connector & (Terminal No.) |
|---|---|---|---|
| 7 | COMM | Green/Black | C277a (15) |
| 22 | COMM | Gray/Red | C277a (14) |
| 24 | COMM | Green/White | C277a (5) |
| 25 | COMM | White | C277a (6) |
| 31 | COMM | Pink/Black | C277a (7) |
| 33 | COMM | Red/Green | C277b (17) |