2002-2004 models

If the ECM/PCM does not communicate with a scan tool, HDS, or I/M test equipment, do this troubleshooting procedure.

1. Measure voltage between DLC terminal No. 16 and body ground.
   Fig 1: Measuring Voltage Between DLC Terminal 16 And Body Ground

   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Is there battery voltage? 

   1. YES -  Go to step 2.
   2. NO -  Repair open in the wire between DLC terminal No. 16 and the No. 9 BACK UP (7.5 A) fuse in the underhood fuse/relay box.
2. Measure voltage between DLC terminals No. 4 and No. 16.
   Fig 2: Measuring Voltage Between DLC Terminals 4 And 16

   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Is there battery voltage? 

   1. YES -  Go to step 3.
   2. NO -  Repair open in the wire between DLC terminal No. 4 and body ground (G401).
3. Measure voltage between DLC terminals No. 5 and No. 16.
   Fig 3: Measuring Voltage Between DLC Terminals 5 And 16

   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Is there battery voltage? 

   1. YES -  Go to step 4.
   2. NO -  Repair open in the wire between DLC terminal No. 5 and ECM/PCM (E3) or ECM/PCM (A23, A24) and body ground.
4. Turn the ignition switch ON (II).
5. Measure voltage between DLC terminals No. 5 and No. 7.
   Fig 4: Measuring Voltage Between DLC Terminals 5 And 7

   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Is there 8.5 V or more? 

   1. YES -  Go to step  10.
   2. NO -  Go to step 6.
6. Turn the ignition switch OFF.
7. Disconnect ECM/PCM connector E (31P). Make sure a scan tool or the HDS is disconnected from the DLC.
8. Check for continuity between DLC terminal No. 7 and body ground.
   Fig 5: Checking Continuity Between DLC Terminal 7 And Body Ground

   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Is there continuity? 

   1. YES -  Repair short to ground in the wire between DLC terminal No. 7 and the ECM/PCM (E23). After repairing the wire, check for a DTC with a scan tool or the HDS, and go to the indicated DTC'S TROUBLESHOOTING .
   2. NO -  Go to step 9.
9. Check for continuity between DLC terminal No. 7 and ECM/PCM terminal E23.
   Fig 6: Checking Continuity Between DLC Terminal 7 And ECM/PCM Terminal E23

   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Is there continuity? 

   1. YES -  Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see HOW TO UPDATE THE ECM/PCM ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT  ).
   2. NO -  Repair open in the wire between DLC terminal No. 7 and the ECM/PCM (E23). After repairing the wire, check for a DTC with a scan tool or the HDS, and go to the indicated DTC'S TROUBLESHOOTING .
10. Turn the ignition switch OFF.
11. Disconnect ECM/PCM connector E (31P). Make sure a scan tool or the HDS is disconnected from the DLC.
12. Turn the ignition switch ON (II).
13. Measure voltage between DLC terminals No. 5 and No. 7.
    Fig 7: Measuring Voltage Between DLC Terminals 5 And 7

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there 0 V? 

    1. YES -  Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see HOW TO UPDATE THE ECM/PCM ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT  ).
    2. 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 a DTC with a scan tool or the HDS, and go to the indicated DTC'S TROUBLESHOOTING .