MIL Circuit Troubleshooting

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 16 .
NO | - | Go to Step 5 .
Turn the ignition switch OFF. Turn the ignition switch ON (II), 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?
YES | - | Go to Step 10 .
NO | - | Go to ‘‘DLC Circuit Troubleshooting''. If no problem is found in the DLC troubleshooting, go to step 20.
Check for Temporary DTCs or DTCs in the DTCs MENU 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. Is 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. Is a short indicated?
YES | - | Go to Step 13 .
NO | - | Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. ■
Turn the ignition switch OFF, and wait 30 seconds. Disconnect ECM connector No. 2 (58P). Check for continuity between ECM connector No. 2 terminal No. 20 and body ground. Is there continuity?
YES | - | Repair short in the wire between the DLC and ECM connector No. 2 terminal No. 20.■
NO | - | Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. ■
Try to start the engine. Does the engine start?
YES | - | Go to Step 17 .
NO | - | Go to Step 21 .
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?
YES | - | Go to Step 20 .
NO | - | Go to ‘‘DLC Circuit Troubleshooting''. If no problem is found in the DLC troubleshooting, go to Step 20 .
Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS. Is DTC U0073 and/or U0155 indicated?
YES | - | Go to the indicated DTC's troubleshooting.■
NO | - | Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. ■
Press the inertia switch button. Try to start the engine. Does the engine start?
YES | - | Troubleshooting is complete.■
NO | - | Go to Step 23 .
Check PGM-FI main relay 1. Is PGM-FI main relay 1 OK?
YES | - | Go to Step 24 .
NO | - | Replace PGM-FI main relay 1.■
Inspect No. 8 FI ECU (ECM) (20 A) fuse inthe under-hood fuse/relay box. Is the fuse OK?
YES | - | Go to Step 31 .
NO | - | Go to Step 25 .
Disconnect PGM-FI main relay 1. |

Check for continuity between body ground and PGM-FI main relay 1 4P connector terminals No. 1 and No. 4 individually. Is there continuity?
YES | - | Repair short in the wire between PGM-FI main relay 1 and No. 8 FI ECU (ECM) (20 A) fuse. Also replace No. 8 FI ECU (ECM) (20 A) fuse.■
NO | - | Go to Step 27 .
Turn the ignition switch OFF, and wait 30 seconds. Disconnect ECM connector No. 2 (58P). Disconnect the fuel rail pressure control valve 2P connector. |

Check for continuity between PGM-FI main relay 1 4P connector terminal No. 2 and body ground. Is there continuity?
YES | - | Repair short in the wire between PGM-FI main relay 1, fuel rail pressure control valve and ECM connector No. 2 terminal No. 1, No. 3 or No. 5. Also replace No. 8 FI ECU (ECM) (20 A) fuse.■
NO | - | Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. ■
Turn the ignition switch OFF. Disconnect PGM-FI main relay 1. |

Measure voltage between body ground and PGM-FI main relay 1 4P connector terminals No. 1 and No. 4 individually. Is there battery voltage?
YES | - | Go to Step 34 .
NO | - | Repair open in the wire between PGM-FI main relay 1 and No. 8 FI ECU (ECM) (20 A) fuse.■
Disconnect ECM connector No. 2 (58P). |

Connect PGM-FI main relay 1 4P connector terminal No. 3 to body ground with a jumper wire. |

Check for continuity between ECM connector No. 2 terminal No. 19 and body ground. Is there continuity?
YES | - | Go to Step 40 .
NO | - | Go to Step 37 .
Disconnect the inertia switch 3P connector. |

Connect inertia switch 3P connector terminals No. 1 and No. 3 with a jumper wire. |

Check for continuity between ECM connector No. 2 terminal No. 19 and body ground. Is there continuity?
YES | - | Replace the inertia switch .■
NO | - | Repair open in the wire between PGM-FI main relay 1 and ECM connector No. 2 terminal No. 19.■

Measure voltage between ECM connector No. 2 terminal No. 35 and body ground. Is there battery voltage?
YES | - | Go to Step 42 .
NO | - | Go to Step 41 .
Inspect No. 18 IG ACG (15 A) fuse in the under-dash fuse/relay box. Is the fuse OK?
YES | - | Repair open in the wire between No. 18 IG ACG (15 A) fuse and ECM connector No. 2 terminal No. 1.■
NO | - | Repair short in the wire between No. 18 IG ACG (15 A) fuse and ECM connector No. 2 terminal No. 1.■

Check for continuity between PGM-FI main relay 1 4P connector terminal No. 2 and ECM connector No. 2 terminals No. 1, No. 3, and No. 5 individually. Is there continuity?
YES | - | Go to Step 43 .
NO | - | Repair open in the wire between PGM-FI main relay 1 and ECM connector No. 2 terminal No. 1, No. 3 or No. 5.■

Check for continuity between body ground and ECM connector No. 2 terminals No. 2, No. 4, and No. 6 individually. Is there continuity?
YES | - | Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. ■
NO | - | Repair open in the wire between PGM-FI main relay 1 and ECM connector No. 2 terminal No. 1, No. 3 or No. 5.■