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HOMESERVICE MANUALSACURA20043.5RLREPAIR AND DIAGNOSISENGINE PERFORMANCESYSTEMENGINE PERFORMANCE SYSTEM SELF-DIAGNOSTICSDIAGNOSTIC CIRCUIT CHECKMALFUNCTION INDICATOR LIGHT (MIL) CIRCUIT TROUBLESHOOTING (2004 3.5RL)
2004 Acura 3.5RL

Malfunction Indicator Light (Mil) Circuit Troubleshooting (2004 3.5RL)

2004 Acura 3.5RLSECTION Malfunction Indicator Light (Mil) Circuit Troubleshooting (2004 3.5RL)
NOTE: If either of these symptoms is intermittent, check for the following problems:
  1. The MIL never comes on after the ignition switch is turned ON (II):
    • A loose No. 6 ECU (PCM) (20-amp) fuse in underdash fuse/relay box.
    • A loose No. 22 FUEL PUMP (20-amp) fuse in underdash fuse/relay box.
    • An intermittent short in wire between PCM 26-pin connector A terminal No. 7 and the gauge assembly.
    • An intermittent short in wire between PCM 22-pin connector D terminal No. 10 and the MAP sensor.
    • An intermittent short in wire between PCM 22-pin connector D terminal No. 21 and TP sensor, EGR valve position sensor, fuel tank pressure sensor, TCS control valve angle sensor.
    • A loose No. 25 IG COIL (30-amp) fuse in underdash fuse/relay box.
    • PGM-FI main relay.
  2. The MIL stays on or comes on after 2 seconds with the ignition switch turned ON (II):
    • An intermittent short in wire between PCM 12-pin connector C terminal No. 5 and the 2-pin Service Check Connector and 16-pin Data Link Connector (DLC).
    • An intermittent open in wires between PCM 22-pin connector D terminal No. 22 and the 2-pin Service Check Connector.
    • An intermittent short in wire between PCM 26-pin connector A terminal No. 7 and the gauge assembly.

See OBDII scan tool or Honda Diagnostic System (HDS) user's manual for specific operating instructions.
  1. Turn ignition switch ON (II) and watch the Malfunction Indicator Light (MIL). If MIL comes on and stays on, go to step  10 . If MIL does not come on and stay on, go to next step.
  2. Turn ignition switch off. Turn ignition switch ON (II). If low oil pressure indicator light comes on, go to next step. If low oil pressure indicator light does not come on, check the following:
    • Repair open or short in wire between gauge relay and gauge assembly.
    • Repair open or short in wire between METER (15-amp) fuse and gauge relay.
    • Repair open or short in wire between No. 13 METER (7.5-amp) fuse and gauge relay.
    • Test the gauge relay.
    • Replace METER (15-amp) fuse and/or No. 13 METER (7.5-amp) fuse.
  3. Attempt to start engine. If engine starts, go to step  15 . If engine does not start, check No. 6 ECU (PCM) (20-amp) fuse in underdash fuse/relay box. If fuse is okay, go to next step. If fuse is not okay, check the following:
    • Repair short in wire between No. 6 ECU (PCM) (20-amp) fuse and PGM-FI main relay.
    • Repair short in wire between PGM-FI main relay and PCM, fuel injectors, or Idle Air Control (IAC) valve.
    • Repair short in wire between fuel injectors and IAC valve.
    • Replace No. 6 ECU (PCM) (20-amp) fuse.
  4. Inspect No. 25 IG COIL (30-amp) fuse in underdash fuse/relay box. If fuse is okay, go to next step. If fuse is not okay, check the following:
    • Repair short in wire between No. 25 IG COIL (30-amp) fuse and PGM-FI main relay.
    • Replace No. 25 IG COIL (30-amp) fuse.
  5. Disconnect fuel injector and IAC valve electrical harness connectors. Turn ignition switch ON (II). Individually measure voltage between body ground and PCM 26-pin connector A terminal No. 13 (Yellow/Black wire) and PCM 16-pin connector B terminal No. 1 (Yellow/Black wire). If battery voltage is present, go to next step. If battery voltage is not present, check the following:
    • Repair open in Yellow/Black wire(s) between PCM 26-pin connector A terminal No. 13, PCM 16-pin connector B terminal No. 1 and PGM-FI main relay.
    • Check for poor connections or loose wires at PGM-FI main relay.
    • Check PGM-FI main relay. See PGM-FI MAIN RELAY CIRCUIT TESTING under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article.
    • Repair open or short in wire between immobilizer unit and PCM.
  6. Reconnect fuel injector and IAC valve electrical harness connectors. Individually measure voltage between body ground and PCM 26-pin connector A terminals No. 12 (Black wire), No. 25 (Black wire) and No. 26 (Brown/Black wire). Also measure voltage between body ground and PCM 16-pin connector B terminal No. 9 (Brown/Black wire). If voltage is less than one volt, go to next step. If voltage is not less than one volt, repair open circuit in wire(s) between PCM and ground terminal G101 that had more than one volt.
  7. Measure voltage between body ground and PCM 22-pin connector D terminals No. 10 (Yellow/Red wire) and No. 21 (Yellow/Blue wire) individually. If about 5 volts are not present, go to next step. If about 5 volts are present, substitute a known-good PCM, and recheck. If symptom or indication goes away, replace original PCM.
  8. While measuring voltage between body ground and PCM 22-pin connector D terminals No. 10 (Yellow/Red wire) and No. 21 (Yellow/Blue wire) individually, disconnect 3-pin connector from following sensors one at a time:
    • MAP sensor
    • TP sensor
    • EGR valve lift sensor
    • Fuel tank pressure sensor
    • VSA control valve angle sensor
    If about 5 volts is present, replace sensor that had about 5 volts. If about 5 volts is not present, go to next step.
  9. Turn ignition switch off. Disconnect PCM 22-pin connector D. Individually check for continuity between body ground and PCM 22-pin connector D terminals No. 10 (Yellow/Red wire) and No. 21 (Yellow/Blue wire). If continuity is present, repair short in wiring between MAP sensor, TP sensor, EGR valve position sensor, fuel tank pressure sensor, or VSA control valve angle sensor and PCM. If continuity is not present, substitute a known-good PCM, and recheck. If symptom or indication goes away, replace original PCM.
  10. Turn ignition switch off. Connect scan tool or HDS. Turn ignition switch ON (II), and read DTCs with scan tool or HDS. If any DTCs are indicated, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS  and repair as necessary. If no DTCs are indicated, go to next step.
  11. Turn ignition switch off. Turn ignition switch ON (II). Measure voltage between PCM 12-pin connector C terminal No. 5 (Red wire) and body ground. If about 5 volts or battery voltage is present, go to next step. If about 5 volts or battery voltage is not present, repair short in wire between Service Check Connector, DLC and PCM.
  12. Turn ignition switch off. Disconnect PCM 22-pin connector D. Check for continuity between DLC 16-pin connector terminal No. 7 (Lt. Green wire) and body ground. If continuity is not present, go to next step. If continuity is present, repair short in Lt. Green wire between DLC and PCM 22-pin connector D terminal No. 4.
  13. Check for continuity in Lt. Green wire between DLC 16-pin connector terminal No. 7 and PCM 22-pin connector D terminal No. 4. If continuity is present, go to next step. If continuity is not present, repair open in Lt. Green wire between DLC and PCM 22-pin connector D terminal No. 4.
  14. Turn ignition switch ON (II). If MIL does come on, repair short in Lt. Green/Red wire between gauge assembly and PCM 26-pin connector A terminal No. 7. If MIL does not come on, substitute a known-good PCM, and recheck. If symptom or indication goes away, replace original PCM.
  15. Turn ignition switch off. Using a jumper wire, connect PCM 26-pin connector A terminal No. 7 (Lt. Green/Red wire) to body ground. Turn ignition switch ON (II). If MIL comes on, substitute a known-good PCM, and recheck. If symptom or indication goes away, replace original PCM. If MIL does not come on, check the following:
    • Repair open in wires between PCM 26-pin connector A terminal No. 7 and gauge assembly.
    • Replace MIL bulb.
RENDER: 1.0x

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