MIL Circuit Troubleshooting

NOTE: Information marked with an asterisk ( * ) applies to RHD model. Turn the ignition switch ON (II). Do the gauge self-diagnostic procedure. Does the MIL indicator flash?
YES | - | Go to Step 3 .
NO | - | Substitute a known-good gauge assembly, and recheck. If the MIL circuit is OK, replace the original gauge assembly.■
Turn the ignition switch OFF. Turn the ignition switch ON (II), and watch the MIL. Does the MIL stay off?
YES | - | Go to Step 17 .
NO | - | Go to Step 5 .
Turn the ignition switch OFF. Turn the ignition switch ON (II), and wait 20 seconds, and watch the MIL. Does the MIL stay on or flash?
YES | - | Go to Step 7 .
NO | - | The MIL circuit is OK.■
Turn the ignition switch OFF. Connect the HDS. Turn the ignition switch ON (II), and read the HDS. Does the HDS communicate with the ECM/PCM?
YES | - | Go to Step 10 .
NO | - | Go to ‘‘DLC Circuit Troubleshooting''. If no problem is found in the DLC troubleshooting, go to Step 21 .
Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated?
YES | - | Go to the indicated DTC's troubleshooting.■
NO | - | Go to Step 11 .
Check the MIL in the DATA LIST with the HDS. Does it ON indicated?
YES | - | Go to Step 12 .
NO | - | Substitute a known-good gauge assembly, and recheck. If the MIL circuit is OK, replace the original gauge assembly.■
Check the SCS in the DATA LIST with the HDS. Does it indicate short?
YES | - | Go to Step 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 .■
Turn the ignition switch OFF. Jump the SCS line with the HDS. Disconnect ECM/PCM connector E (31P). 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.■
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 .■
Try to start the engine. Does the engine start and idle smoothly?
YES | - | Go to Step 18 .
NO | - | Go to Step 22 .
Turn the ignition switch OFF. Connect the HDS. Turn the ignition switch ON (II), and read the HDS. Does the HDS communicate with the ECM/PCM?
YES | - | Go to Step 21 .
NO | - | Go to ‘‘DLC Circuit Troubleshooting''. If no problem is found in the DLC troubleshooting, go to Step 21 .
Check for Temporary DTCs or DTCs with the HDS. Is DTC U0073 and/or U0155 indicated?
YES | - | Go to the indicated DTC's troubleshooting.■
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 .■
Turn the ignition switch OFF. Inspect the No. 23 +B IG MAIN (50 A) fuse in the under-hood fuse/relay box. Is the fuse OK?
YES | - | Repair open in the wire between the No. 23 +B IG MAIN (50 A) fuse and the ignition switch. If the wire is OK, go to Step 24 .
NO | - | Repair short in the wire between No. 23 +B IG MAIN (50 A) fuse and the under-dash fuse/relay box. Also replace the No. 23 +B IG MAIN (50 A) fuse.■
Inspect the No. 8 FI ECU (ECM/PCM) (15 A) fuse in the under-hood fuse/relay box. Is the fuse OK?
YES | - | Go to Step 31 .
NO | - | Go to Step 25 .
Remove the blown No. 8 FI ECU (ECM/PCM) (15 A) fuse from the under-dash fuse/relay box. |

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

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) (15 A) fuse and PGM-FI main relay 1 (FI MAIN). Also replace the No. 8 FI ECU (ECM/PCM) (15 A) fuse.■
NO | - | Go to Step 28 .

Disconnect following components or connectors, 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) A/F sensor relay Throttle actuator control module relay ECM/PCM connector A (31P) Each injector 2P connector Camshaft position (CMP) sensor B 3P connector Crankshaft position (CKP) sensor 3P connector Does continuity go away when one of the above components is disconnected?
YES | - | 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) (15 A) fuse.■
NO | - | Go to Step 29 .
Disconnect the connectors of all these components. PGM-FI main relay 2 (FUEL PUMP) A/F sensor relay Throttle actuator control module relay ECM/PCM connector A (31P) Injectors Camshaft position (CMP) sensor B Crankshaft position (CKP) sensor |

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) (15 A) fuse.■
NO | - | Replace PGM-FI main relay 1 (FI MAIN). Also replace the No. 8 FI ECU (ECM/PCM) (15 A) fuse.■
Inspect the No. 19 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box. Is the fuse OK?
YES | - | Go to Step 44 .
NO | - | Go to Step 32 .
Remove the blown No. 19 FUEL PUMP (15 A) fuse from the under-dash fuse/relay box. Jump the SCS line with the HDS. Disconnect ECM/PCM connector E (31P). |

Check for continuity between ECM/PCM connector terminal E9 and body ground. Is there continuity?
YES | - | Go to Step 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 .■

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

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 (15 A) fuse and the ECM/PCM (E9), or between the No. 19 FUEL PUMP (15 A) fuse and PGM-FI main relay 2 (FUEL PUMP), or between the No. 19 FUEL PUMP (15 A) fuse and the immobilizer control unit. Also replace the No. 19 FUEL PUMP (15 A) fuse.■
NO | - | Go to Step 38 .
Remove the trunk floor trim panel. Remove the access panel from the floor. Disconnect the fuel pump 5P connector. |

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 (15 A) fuse.■
NO | - | Go to Step 42 .

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

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 (15 A) fuse.■
NO | - | Check the fuel pump, and replace it if necessary. Also replace the No. 19 FUEL PUMP (15 A) fuse.■
Jump the SCS line with the HDS. Disconnect ECM/PCM connector E (31P). Turn the ignition switch ON (II). |

Measure voltage between ECM/PCM connector terminal E9 and body ground. Is there battery voltage?
YES | - | Go to Step 48 .
NO | - | Repair open in the wire between the No. 19 FUEL PUMP (15 A) fuse and the ECM/PCM (E9).■

Measure voltage between ECM/PCM connector terminal E7 and body ground. Is there battery voltage?
YES | - | Go to Step 53 .
NO | - | Go to Step 49 .
Turn the ignition switch OFF. |

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

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 Step 52 .
NO | - | Repair open in the wire between the No. 8 FI ECU (ECM/PCM) (15 A) fuse and PGM-FI main relay 1 (FI MAIN).■

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 .■
NO | - | Repair open in the wire between PGM-FI main relay 1 (FI MAIN) and the ECM/PCM (E7).■
Reconnect ECM/PCM connector E (31P). Turn the ignition switch ON (II). |

Measure voltage between body ground and ECM/PCM connector terminals A2 and A3 individually. Is there battery voltage?
YES | - | Go to Step 62 .
NO | - | Go to Step 56 .
Turn the ignition switch OFF. |

Remove PGM-FI main relay 1 (FI MAIN) (A). Turn the ignition switch ON (II). |

Measure voltage between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No. 2 and body ground. Is there battery voltage?
YES | - | Go to Step 60 .
NO | - | Repair open in the wire between the No. 8 FI ECU (ECM/PCM) (15 A) fuse and PGM-FI main relay 1 (FI MAIN).■
Turn the ignition switch OFF. |

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

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).■
NO | - | Go to Step 63 .

Measure voltage between body ground and ECM/PCM connector terminals A21. Is there about 5 V?
YES | - | Go to Step 71 .
NO | - | Go to Step 64 .
Turn the ignition switch OFF. |

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 Accelerator pedal position (APP) sensor Input shaft (mainshaft) speed sensor (A/T) Is there about 5 V?
YES | - | Replace the sensor that restored 5 V when disconnected.■
NO | - | Go to Step 66 .
Turn the ignition switch OFF. Jump the SCS line with the HDS. Disconnect the connectors from these sensors: Manifold absolute pressure (MAP) sensor Accelerator pedal position (APP) sensor Input shaft (mainshaft) speed sensor (A/T) Disconnect ECM/PCM connector A (31P). |

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, the APP sensor, the input shaft (mainshaft) speed sensor (A/T).■
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 .■

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 goes away with a known-good ECM/PCM, replace the original ECM / PCM .■
NO | - | Go to Step 72 .
Turn the ignition switch OFF. |

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). Accelerator pedal position (APP) sensor EGR valve (K20Z2 engine) Output shaft (countershaft) speed sensor Is there about 5 V?
YES | - | Replace the sensor that restored 5 V when disconnected.■
NO | - | Go to Step 74 .
Turn the ignition switch OFF. Jump the SCS line with the HDS. Disconnect the connector from these sensors: Accelerator pedal position (APP) sensor EGR valve (K20Z2 engine) Output shaft (countershaft) speed sensor Disconnect ECM/PCM connector A (31P). |

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 APP sensor, the EGR valve (K20Z2 engine), the output shaft (countershaft) speed sensor.■
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 .■