MIL Circuit Troubleshooting

1.Turn the ignition switch ON (II).

2.Do the gauge self-diagnostic procedure.

Does the MIL indicator flash?


YES - Go to 3.


NO - Substitute a known-good gauge assembly, and recheck. If the MIL circuit is OK, replace the original gauge assembly.n


3.Turn the ignition switch OFF.

4.Turn the ignition switch ON (II), and watch the MIL.

Does the MIL stay off?


YES - Go to 17.


NO - Go to 5.


5.Turn the ignition switch OFF.

6.Turn the ignition switch ON (II), and wait 20 seconds, and watch the MIL.

Does the MIL stay on or flash more than 5 times?


YES - Go to 7.


NO - The MIL circuit is OK.n


7.Turn the ignition switch OFF.

8.Connect the Honda PGM Tester or the HDS..

9.Turn the ignition switch ON (II), and read the Honda PGM Tester or the HDS.

Does the Honda PGM Tester or the HDS communicate with the ECM/PCM?


YES - Go to 10.


NO - Go to ‘‘DLC Circuit Troubleshooting''. If no problem is found in the DLC troubleshooting, go to 21.


10.Check for Temporary DTCs or DTCs in the DTCs MENU with the Honda PGM Tester or the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - Go to the DTC Troubleshooting Index.


NO - Go to 11.


11.Check the MIL in the DATA LIST with the Honda PGM Tester or the HDS.

Does it ON indicated?


YES - Go to 12.


NO - Substitute a known-good gauge assembly, and recheck. If the MIL circuit is OK, replace the original gauge assembly.n

12.Check the SCS in the DATA LIST with the Honda PGM Tester or the HDS.

Does it indicate short?


YES - Go to 13.


NO - 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.n


13.Turn the ignition switch OFF.

14.Jump the SCS line with the Honda PGM Tester or the HDS.

15.Disconnect ECM/PCM connector E (31P).

16.Check for continuity between ECM/PCM connector terminal E29 and body ground.

Is there continuity?


YES - Repair short in the wire between the ECM/PCM (E29) and the DLC.n


NO - 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.n

17.Try to start the engine.

Does the engine start?


YES - Go to 18.


NO - Go to 22.


18.Turn the ignition switch OFF.

19.Connect the Honda PGM Tester or the HDS.

20.Turn the ignition switch ON (II), and read the Honda PGM Tester or the HDS.

Does the Honda PGM Tester or the HDS communicate with the ECM/PCM?


YES - Go to 21.


NO - Go to ‘‘DLC Circuit Troubleshooting''. If no problem is found in the DLC torubleshooting, go to 21.


21.Check for Temporary DTCs or DTCs in the DTCs MENU with the Honda PGM Tester or the HDS.

Is DTC U0073 and/or U0155 indicated?


YES - Go to indicated DTCs troubleshooting.n


NO - 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.n

22.Turn the ignition switch OFF.

23.Inspect the No. 23 +B IG MAIN (50A) fuse in the under-hood fuse/relay box.

Is the fuse OK?


YES - Repair open in the wire between the NO. 20 IG (50A) fuse and the ignition switch. If the wire is OK, go to 24.


NO - Repair short in the wire between NO. 23 +B IG MAIN (50A) fuse and the under-dash fuse/relay box. Also replace the NO. 23 +B IG MAIN (50A) fuse.n


24.Inspect the No. 8 FI ECU (ECM/PCM) (15A) fuse in the under-hood fuse/relay box.

Is the fuse OK?


YES - Go to 31.


NO - Go to 25.


25.Remove the blown No. 8 FI ECU (ECM/PCM) (15A) fuse from the under-dash fuse/relay box.

26.Remove the kick panel, then remove PGM-FI main relay 1 (FI MAIN) (A) from the under-hood fuse/relay box.

27.Check for continuity between body ground and PGM-FI main relay 1 (FI MAIN) 4P connector terminals No. 2 and No. 3 individually.

Is there continuity?


YES - Repair short in the wire between the No. 8 FI ECU (ECM/PCM) (15A) fuse and PGM-FI main relay 1. Also replace the No. 8 FI ECU (ECM/PCM) (15A) fuse.n


NO - Go to 28.

28.Disconnect each of the components or connectors below, one at a time, and check for continuity between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No. 1 and body ground.

  • PGM-FI main relay 2 (FUEL PUMP)
  • ECM/PCM connector A (31P)
  • Each injector 2P connector
  • Idle air control (IAC) valve 3P connector
  • Camshaft position (CMP) sensor B 3P connector
  • Crankshaft position (CKP) sensor 3P connector

Is there continuity?


YES - Go to 29.


NO - Replace the component that made the short to body ground go away when disconnected. If the item is the  ECM/PCM, 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.
Also replace the No. 8 FI ECU ( ECM/PCM) (15A) fuse.n


29.Disconnect the connectors of all these components.

  • PGM-FI main relay 2 (FUEL PUMP)
  • ECM/PCM connector A (31P)
  • Injectors
  • Idle air control (IAC) valve
  • Camshaft position (CMP) sensor B
  • Crankshaft position (CKP) sensor

30.Check for continuity between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No. 1 and body ground.

Is there continuity?


YES - Repair short in the wire between PGM-FI main relay 1 (FI MAIN) and each item. Also replace the No. 8 FI ECU (ECM/PCM) (15A) fuse.n


NO - Replace PGM-FI main relay 1 (FI MAIN). Also replace the No. 8 FI ECU ( ECM/PCM) (15A) fuse.n


31.Inspect the No. 19 FUEL PUMP (15A) fuse in the under-dash fuse/relay box.

Is the fuse OK?


YES - Go to 44.


NO - Go to 32.


32.Remove the blown No. 19 FUEL PUMP (15A) fuse from the under-dash fuse/relay box.

33.Jump the SCS line with the Honda PGM Tester or the HDS.

34.Disconnect ECM/PCM connector E (31P).

35.Check for continuity between ECM/PCM connector terminal E9 and body ground.

Is there continuity?


YES - Go to 36.


NO - Replace the No. 19 FUEL PUMP (15 A) fuse, and 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.n


36.Remove the kick panel, then remove the PGM-FI main relay 2 (FUEL PUMP) (A) from the under-hood fuse/relay box.

37.Check for continuity between ECM/PCM connector terminal E9 and body ground.

Is there continuity?


YES - Repair short in the wire between the No. 19 FUEL PUMP (15A) fuse and the ECM/PCM (E9), or between the No. 19 FUEL PUMP (15A) fuse and the PGM-FI main relay 2 (FUEL PUMP). Also replace the No. 19 FUEL PUMP (15A) fuse.n


NO - Go to 38.


38.Remove the trunk floor trim panel.

39.Remove the access panel from the floor.

40.Disconnect the fuel pump 5P connector.

41.Check for continuity between fuel pump 5P connector terminal No. 5 and body ground.

Is there continuity?


YES - Repair short in the wire between the fuel pump and PGM-FI main relay 2 (FUEL PUMP). Also replace the No. 19 FUEL PUMP (15A) fuse.n


NO - Go to 42.


42.Reinstall PGM-FI main relay 2 (FUEL PUMP) (A).

43.Check for continuity between fuel pump 5P connector terminal No. 5 and body ground.

Is there continuity?


YES - Replace PGM-FI main relay 2 (FUEL PUMP). Also replace the No. 19 FUEL PUMP (15A) fuse.n


NO - Check the fuel pump, and replace it if necessary. Also replace the No. 19 FUEL PUMP (15A) fuse.n


44.Jump the SCS line with the Honda PGM Tester or the HDS.

45.Disconnect ECM/PCM connector E (31P).

46.Turn the ignition switch ON (II).

47.Measure voltage between ECM/PCM connector terminal E9 and body ground.

Is there battery voltage?


YES - Go to 48.


NO - Repair open in the wire between the No. 19 FUEL PUMP (15A) fuse and the ECM/PCM (E9).n

48.Measure voltage between ECM/PCM connector terminal E7 and body ground.

Is there battery voltage?


YES - Go to 53.


NO - Go to 49.


49.Turn the ignition switch OFF.

50.Remove the kick panel, then remove the PGM-FI main relay 1 (FI MAIN) (A) from the under-hood fuse/relay box.

51.Measure voltage between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No. 3 and body ground.

Is there battery voltage?


YES - Go to 52.


NO - Repair open in the wire between the No. 8 FI ECU (ECM/PCM) (15A) fuse and PGM-FI main relay 1.n


52.Check for continuity between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No. 4 and ECM/PCM connector terminal E7.

Is there continuity?


YES - Test PGM-FI main relay 1 (FI MAIN). If the relay is OK, 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.n


NO - Repair open in the wire between PGM-FI main relay 1 (FI MAIN) and the ECM/PCM (E7).n

53.Reconnect ECM/PCM connector E (31P).

54.Turn the ignition switch ON (II).

55.Measure voltage between body ground and ECM/PCM connector terminals A2 and A3 individually.

Is there battery voltage?


YES - Go to 62.


NO - Go to 56.


56.Turn the ignition switch OFF.

57.Remove PGM-FI main relay 1 (FI MAIN) (A).

58.Turn the ignition switch ON (II).

59.Measure voltage between PGM-FI main relay 1 4P connector terminal No. 2 and body ground.

Is there battery voltage?


YES - Go to 60.


NO - Repair open in the wire between the No. 8 FI ECU (ECM/PCM) (15A) fuse and PGM-FI main relay 1 (FI MAIN).n


60.Turn the ignition switch OFF.

61.Check for continuity between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No. 1 and ECM/PCM connector terminals A2 and A3 individually.

Is there continuity?


YES - Replace PGM-FI main relay 1 (FI MAIN).n


NO - Repair open in the wire between PGM-FI main relay 1 (FI MAIN) and the ECM/PCM (A2, A3).n

62.Measure voltage between body ground and ECM/PCM connector terminals A4, A5, A8, and A9 individually.

Is there more than 0.2 V?


YES - Repair open in the wire(s) that had more than 0.2 V between G101 and the ECM/PCM (A4, A5, A8, A9).n


NO - Go to 63.


63.Measure voltage between body ground and ECM/PCM connector terminals A21.

Is there more than 5 V?


YES - Go to 71.


NO - Go to 64.

64.Turn the ignition switch OFF.

65.Disconnect the connector from each of these sensors, one at a time, and measure voltage between body ground and ECM/PCM connector terminal A21 with the ignition switch ON (II).

  • Manifold absolute pressure (MAP) sensor
  • Accelera tor pedal position (APP) sensor (with Electronic throttle control system)
  • Mainshaft speed sensor (A/T)

Is there about 5 V?


YES - Replace the sensor that restored 5 V when disconnected.n


NO - Go to 66.


66.Turn the ignition switch OFF.

67.Jump the SCS line with the Honda PGM Tester or the HDS.

68.Disconnect the connectors from the following sensors.

  • Manifold absolute pressure (MAP) sensor
  • Accelera tor pedal position (APP) sensor (with Electronic throttle control system)
  • Countershaft speed sensor (A/T)

69.Disconnect ECM/PCM connector A (31P).

70.Check for continuity between ECM/PCM connector terminal A21 and body ground.

Is there continuity?


YES - Repair short in the wire between ECM/PCM (A21) and the MAP sensor, APP sensor (with Electronic throttle control system), mainshaft speed sensor (A/T).n


NO - 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 does away with a known-good ECM/PCM, replace the original ECM/PCM.n


71.Measure voltage between body ground and ECM/PCM connector terminals A20.

Is there about 5 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 does away with a known-good ECM/PCM, replace the original ECM/PCM.n


NO - Go to 72.

72.Turn the ignition switch OFF.

73.Disconnect the connector from each of these sensors, one at a time, and measure voltage between body ground and ECM/PCM connector terminal A20 with the ignition switch ON (II).

  • Throttle position (TP) sensor
  • Accelerator pedal position (APP) sensor (with Electronic throttle control system)
  • EGR valve
  • Countershaft speed sensor (A/T)

Is there about 5 V?


YES - Replace the sensor that restored 5 V when disconnected.n


NO - Go to 74.


74.Turn the ignition switch OFF.

75.Jump the SCS line with the Honda PGM Tester or the HDS.

76.Disconnect the connector from the following sensors.

  • Throttle position (TP) sensor
  • Accelerator pedal position (APP) sensor (with Electronic throttle control system)
  • EGR valve
  • Countershaft speed sensor (A/T)

77.Disconnect ECM/PCM connector A (31P).

78.Check for continuity between ECM/PCM connector terminal A20 and body ground.

Is there continuity?


YES - Repair short in the wire between the ECM/PCM (A20) and the TP sensor, APP sensor (with Electronic throttle control system), EGR valve countershaft speed sensor (A/T).n


NO - Update the ECM/PCM if it does not have the latest software, or subsutitute a known-good, ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.n