DLC Circuit Troubleshooting

1.Turn the ignition switch ON (II).

2.Measure voltage between data link connector (DLC) terminal No. 16 and body ground.

 

Is there battery voltage?


YES - Go to 3.


NO - Repair open in the wire between DLC terminal No. 16 and the No. 9 BACK UP (10A) fuse in the under-hood fuse/relay box.n


3.Measure voltage between DLC terminals No. 4 and No. 16.

 

Is there battery voltage?


YES - Go to 4.


NO - Repair open in the wire between DLC terminal No. 4 and body ground.n

4.Measure voltage between DLC terminals No. 5 and No. 16.

 

Is there battery voltage?


YES - Go to 5.


NO - Repair open in the wire between DLC terminal No. 5 and the  ECM/ PCM (E3).n


5.Measure voltage between DLC terminals No. 5 and No. 7.

 

Is there 8.5 V or more?


YES - Go to 11.


NO - Go to 6.


6.Turn the ignition switch OFF.

7.Disconnect the negative cable from the battery.

8.Disconnect ECM/PCM connector E (31P). Make sure the Honda PGM Tester is disconnected from the DLC.

9.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).n


NO - Go to 10.


10.Check for continuity between DLC terminal No. 7 and ECM/PCM terminal E23.

 

Is there continuity?


YES - Substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original  ECM/ PCM.n


NO - Repair open in the wire between DLC terminal No. 7 and the  ECM/ PCM (E23).n


11.Turn the ignition switch OFF.

12.Disconnect the negative cable from the battery.

13.Disconnect ECM/PCM connector E (31P). Make sure the Honda PGM Tester is disconnected from the DLC.

14.Reconnect the negative cable to the battery.

15.Turn the ignition switch ON (II).

16.Measure voltage between DLC terminals No. 5 and No. 7.

 

Is there 0 V?


YES - Substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original  ECM/ PCM.n


NO - Repair short to power in the wire between the DLC terminal No. 7 and the  ECM/ PCM (E23).n