MIL Circuit Troubleshooting

NOTE: Information marked with an asterisk ( * ) applies to RHD model.

1. Turn the ignition switch ON (II).

1. 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.■

1. Turn the ignition switch OFF.

1. 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 .

1. Turn the ignition switch OFF.

1. 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.■

1. Turn the ignition switch OFF.

1. Connect the HDS.

1. 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 .

1. 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 .

1. 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.■

1. 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 .■

1. Turn the ignition switch OFF.

1. Jump the SCS line with the HDS.

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

1. 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 .■

1. Try to start the engine.

Does the engine start and idle smoothly?

YES | - | Go to Step 18 .
NO | - | Go to Step 22 .

1. Turn the ignition switch OFF.

1. Connect the HDS.

1. 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 .

1. 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 .■

1. Turn the ignition switch OFF.

1. 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.■

1. 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 .

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

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

1. 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 .

1. 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 .

1. 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

1. 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.■

1. 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 .

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

1. Jump the SCS line with the HDS.

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

1. 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 .■

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

1. 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 .

1. Remove the trunk floor trim panel.

1. Remove the access panel from the floor.

1. Disconnect the fuel pump 5P connector.

1. 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 .

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

1. 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.■

1. Jump the SCS line with the HDS.

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

1. Turn the ignition switch ON (II).

1. 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).■

1. 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 .

1. Turn the ignition switch OFF.

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

1. 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).■

1. 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).■

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

1. Turn the ignition switch ON (II).

1. 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 .

1. Turn the ignition switch OFF.

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

1. Turn the ignition switch ON (II).

1. 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).■

1. Turn the ignition switch OFF.

1. 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).■

1. 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 .

1. 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 .

1. Turn the ignition switch OFF.

1. 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 .

1. Turn the ignition switch OFF.

1. Jump the SCS line with the HDS.

1. Disconnect the connectors from these sensors:
   - Manifold absolute pressure (MAP) sensor
   - Accelerator pedal position (APP) sensor
   - Input shaft (mainshaft) speed sensor (A/T)

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

1. 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 .■

1. 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 .

1. Turn the ignition switch OFF.

1. 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 .

1. Turn the ignition switch OFF.

1. Jump the SCS line with the HDS.

1. Disconnect the connector from these sensors:
   - Accelerator pedal position (APP) sensor
   - EGR valve (K20Z2 engine)
   - Output shaft (countershaft) speed sensor

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

1. 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 .■