Initial Inspection and Diagnostic Overview

How to Troubleshoot Reverse Lockout Systems

How to Troubleshoot Circuits at the ECM Connectors

NOTE: The ECM overwrites data and monitors the EVAP system for about 30 minutes after the ignition switch is turned to LOCK (0) or ACC (I). Jumping the SCS line after turning the ignition switch to LOCK (0) or ACC (I) cancels this function. Disconnecting the ECM during this function, without jumping the SCS line first, can damage the ECM.

1. Make sure the ignition switch is turned to LOCK (0), then jump the SCS line with the HDS.

2. Remove the cover (A).






3. Lift up the under-hood fuse/relay box (D).

4. Remove the coolant reservoir (E). Disconnect ECM connectors A, B, and C.
NOTE: ECM connectors A, B, and C have a symbols (A = (square), B = (triangle) , C = (circle)) embossed on them for identification.






5. When diagnosis/troubleshooting is done at the ECM connector, use the terminal test port (A) above the terminal you need to check.






6. Connect one side of the patch cord's terminals (A) to a commercially available digital multimeter (B), and connect the other side cord's terminals (C) to a commercially available banana jack (Pomona Electronics Tool No. 3563 or equivalent) (D).

7. Gently contact the pin probe (male) at the terminal test port from the terminal side. Do not force the tips into the terminals.
- For accurate results, always use the pin probe (male).

- To prevent damage to the connector terminals, do not insert test equipment probes, paper clips, or other substitutes as they can damage the terminals. Damaged terminals cause a poor connection and an incorrect measurement.

- Do not puncture the insulation on a wire. Punctures can cause poor or intermittent electrical connections.