Data Link Connector: Testing and Inspection
DLC Circuit TroubleshootingIf the ECM/PCM does not communicate with the HDS, a scan tool, or I/M test equipment, do this troubleshooting procedure.
1. Measure voltage between DLC terminal No.16 and body ground.
Is there battery voltage?
YES - Go to step 2.
NO - Repair open in the wire between DLC terminal No.16 and the No.9 BACK UP (7.5 A) fuse in the under-hood fuse/relay box.
2. Measure voltage between DLC terminals No.4 and No.16.
Is there battery voltage?
YES - Go to step 3.
NO - Repair open in the wire between DLC terminal No.4 and body ground.
3. Measure voltage between DLC terminals No.5 and No.16.
Is there battery voltage?
YES - Go to step 4.
NO - Repair open in the wire between DLC terminal No.5 and the ECM/PCM (E3).
4. Turn the ignition switch ON (II).
5. Measure voltage between DLC terminals No.5 and No.7.
Is there 8.5 V or more?
YES - Go to step 10.
NO - Go to step 6.
6. Turn the ignition switch OFF.
7. Disconnect ECM/PCM connector E (31 P). Make sure the HDS or scan tool is disconnected from the DLC.
8. Check for continuity between DLC terminal No.7 and body ground.
Is there continuity?
YES - Repair short to ground in the wire between DLC terminal No.7 and the ECM/PCM (E23). After repairing the wire, check for DTCs with the HDS or a scan tool, and go to the indicated DTC's troubleshooting.
NO - Go to step 9.
9. Check for continuity between DLC terminal No.7 and ECM/PCM terminal E23.
Is there continuity?
YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Repair open in the wire between DLC terminal No.7 and the ECM/PCM (E23). After repairing the wire, check the DTC with the HDS or a scan tool and go to the indicated DTC's troubleshooting.
10. Turn the ignition switch OFF.
11. Disconnect ECM/PCM connector E (31 P). Make sure the HDS or scan tool is disconnected from the DLC.
12. Turn the ignition switch ON (II).
13. Measure voltage between DLC terminals No.5 and No.7.
Is there 0 V?
YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Repair short to power in the wire between the DLC terminal No.7 and the ECM/PCM (E23). After repairing the wire, check for DTCs with the HDS or a scan tool, and go to the indicated DTC's Troubleshooting.