MIL Circuit Troubleshooting

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

Does the MIL stay off?


YES - Go to 16.


NO - Go to 2.


2.Turn the ignition switch OFF.

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

Does the MIL stay on or flash?


YES - Go to 7.


NO - The MIL circuit is OK.n


4.Turn the ignition switch OFF.

5.Connect the HDS.

6.Turn the ignition switch ON (II), and read the HDS.

Does the HDS communicate with the ECM/PCM?


YES - Go to 10.


NO - Go to ‘‘DLC Circuit Troubleshooting''.

7.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 8.


8.Check the MIL in the DATA LIST with the HDS.

Is ON indicated?


YES - Go to 9.


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


9.Check the SCS in the DATA LIST with the HDS.

Is a short indicated?


YES - Go to 10.


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


10.Turn the ignition switch OFF.

11.Jump the SCS line with the HDS.

12.Disconnect ECM/PCM connector E (31P) and the HDS.

13.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), the ABS control unit, the SRS control unit and the DLC (KE, KG, KQ, KS models: service check connector).n


NO - Go to 14.


14.Disconnect the gauge assembly 22P connector.

15.Check for continuity between ECM/PCM connector terminal E31 and body ground.

 

Is there continuity?


YES - Repair short in the wire between the ECM/PCM (E31) and the gauge assembly.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

16.Try to start the engine.

Does the engine not start?


YES - Go to 17.


NO - Go to 25.


17.Turn the ignition switch OFF.

18.Connect ECM/PCM connector terminal E31 to body ground with a jumper wire.

 

19.Turn the ignition switch ON (II).

Is the MIL on?


YES - Go to 22.


NO - Go to 20.


20.Turn the ignition switch OFF.

21.Inspect the No. 10 METER (7.5 A) fuse int the under-dash fuse/relay box.

Is the fuse OK?


YES - Check for an open in the wire between the ECM/PCM (E31) and the gauge assembly. Also check for a blown MIL bulb. If the wires and the bulb are OK, replace the gauge assembly.n


NO - Repair short in the wire between No. 10 METER (7.5 A) fuse and the gauge assembly. Also replace the No. 10 METER (7.5 A) fuse.n

22.Turn the ignition switch OFF.

23.Connect the HDS.

24.Turn the ignition switch ON (II), and read the HDS.

Does the HDS communicate with the ECM/PCM?


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.n


NO - Go the ‘‘DLC Circuit Troubleshooting''.n


25.KE, KG, KS models:
Turn the ignition switch OFF.

26.KE, KG, KS models:
Press the inertia switch button.

27.KE, KG, KS models:
Try to start the engine.

Does the engine start?


YES - Troubleshooting is complete.n


NO - Go to 28.

28.KE, KG, KS models:
Turn the ignition switch OFF.

29.KE, KG, KS models:
Disconnect the inertia switch 3P connector.

30.KE, KG, KS models:
Connect the inertia switch 3P connector terminals No. 1 and No. 3 with a jumper wire.

 

31.KE, KG, KS models:
Try to start the engine.

Does the engine start?


YES - Replace the  inertia switch.n


NO - Go to 32.


32.Inspect the No. 20 IG (50 A) fuse in the under-hood fuse/relay box.

Is the fuse OK?


YES - Repair open in the wire between the No. 20 IG (50 A) fuse and the ignition switch. If the wires are OK, go to 33.


NO - Repair short in the wire between No. 20 IG (50 A) fuse and the under-hood fuse/relay box. Also replace the No. 20 IG (50 A) fuse.n

33.Turn the ignition switch OFF.

34.Inspect the IGP (15 A) fuse in the under-hood subfuse/relay box A.

Is the fuse OK?


YES - Go to 41.


NO - Go to 35.


35.Remove the blown IGP (15 A) fuse in the under-hood subfuse/relay box A.

36.Remove the golve box. Remove the PGM-FI main relay 1 (A).

 

37.Check for continuity between body ground and the PGM-FI main relay 1 4P connector terminals No. 2 and No. 4 individually.

 

Is there continuity?


YES -

  • Repair short in the wire between the IGP (15 A) fuse and the PGM-FI main relay 1. Also replace the IGP (15 A) fuse.n
  • Repair short in the wire between the IGP (15 A) fuse and the No. 2 ENG (30 A) fuse. Also replace the No. 2 ENG (30 A) fuse.n

NO - Go to 38.


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

  • PGM-FI main relay 2
  • ECM/PCM connector A (31P)
  • Each injector 2P connector
  • Throttle actuator control module ralay
  • Camshaft position (CMP) sensor B 3P connector
  • Crankshaft position (CKP) sensor 3P connector

 

Is there continuity?


YES - Go to 39.


NO - Replace the part that made continuity 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. 6 ECU (ECM/PCM) (15 A) fuse.n


39.Disconnect the connectors of all these components:

  • PGM-FI main relay 2
  • ECM/PCM connector A (31P)
  • Injectors
  • Throttle actuator control module relay
  • CMP sensor B
  • CKP sensor

40.Check for continuity between the PGM-FI main relay 1 4P connector terminal No. 1 and body ground.

 

Is there continuity?


YES - Repair short in the wire between the  PGM-FI main relay 1 and each item. Also replace the IGP (15 A) fuse or the No. 2 ENG (30 A) fuse.n


NO - Replace the PGM-FI main relay 1. Also replace the IGP (15 A) fuse or the No. 2 ENG (30 A) fuse.n

41.Inspect the No. 17 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.

Is the fuse OK?


YES - Go to 54.


NO - Go to 42.


42.Remove the blown No. 17 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.

43.Jump the SCS line with the HDS.

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

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

 

Is there continuity?


YES - Go to 46.


NO - Replace the No. 17 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 symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.n

46.Remove the golve box, then remove the PGM-FI main relay 2 (A).

 

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

 

Is there continuity?


YES - Repair short in the wire between the No. 17 FUEL PUMP (15 A) fuse and the inertia switch, or the inertia switch and the ECM/PCM (E9), or the inertia switch and the PGM-FI main relay 2. Also replace the No. 17 FUEL PUMP (15 A) fuse.n


NO - Go to 48.


48.Fold the rear seats forward, and pull back the carpet to expose the access panel.

49.Remove the access panel from the floor.

50.Disconnect the fuel pump 5P connector.

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

 

Is there continuity?


YES - Repair short in the wire between the fuel pump and the PGM-FI main relay 2. Also replace the No. 17 FUEL PUMP (15 A) fuse.n


NO - Go to 52.


52.Reinstall the PGM-FI main relay 2 (A).

 

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

 

Is there continuity?


YES - Replace the  PGM-FI main relay 2. Also replace the No. 17 FUEL PUMP (15 A) fuse.n


NO - Check the fuel pump, and replace it as necessary. Also replace the No. 17 FUEL PUMP (15 A) fuse.n


54.Jump the SCS line with the HDS.

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

56.Turn the ignition switch ON (II).

57.Measure voltage between ECM/PCM connector terminals E9 and body ground.

 

Is there battery voltage?


YES - Go to 58.


NO - Repair open in the wire between the No. 17 FUEL PUMP (15 A) fuse and the ECM/PCM (E9).n

58.Turn the ignition switch OFF.

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

 

Is there battery voltage?


YES - Go to 63.


NO - Go to 60.


60.Remove the glove box, then remove the PGM-FI main relay 1 (A).

 

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

 

Is there battery voltage?


YES - Go to 62.


NO -

  • Repair open in the wire between the IGP (15 A) fuse and the PGM-FI main relay 1.n
  • Repair open in the wire between the IGP (15 A) fuse and the No. 2 ENG (30 A) fuse.n

62.Check for continuity between the PGM-FI main relay 1 4P connector terminal No. 3 and ECM/PCM connector terminal E7.

 

Is there continuity?


YES - Test the PGM-FI main relay 1. 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 symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.n


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

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

64.Turn the ignition switch ON (II).

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

 

Is there battery voltage?


YES - Go to 72.


NO - Go to 66.


66.Turn the ignition switch OFF.

67.Remove the glove box, then remove the PGM-FI main relay 1 (A).

 

68.Turn the ignition switch ON (II).

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

 

Is there battery voltage?


YES - Go to 70.


NO -

  • Repair open in the wire between the IGP (15 A) fuse and the PGM-FI main relay 1.n
  • Repair open in the wire between the IGP (15 A) fuse and the No. 2 ENG (30 A) fuse.n

70.Turn the ignition switch OFF.

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

 

Is there continuity?


YES - Replace the  PGM-FI main relay 1.n


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

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

 

Is there less than 1.0 V?


YES - Repair open in the wire(s) between that had more than 1.0 V between G101 and the ECM/PCM ( A4, A5, A8, A9).n


NO - Go to 73.


73.Turn the ignition switch ON (II).

74.Measure voltage between body ground and ECM/PCM connector terminal A21.

 

Is there about 5 V?


YES - Go to 81.


NO - Go to 75.

75.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
  • Output shaft (countershaft) speed sensor (A/T)

 

Is there about 5 V?


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


NO - Go to 76.


76.Turn the ignition switch OFF.

77.Jump the SCS line with the HDS.

78.Disconnect the connectors from the these sensors:

  • Manifold absolute pressure (MAP) sensor
  • Accelerator pedal position (APP) sensor
  • Output shaft (countershaft) speed sensor (A/T)

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

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

 

Is there continuity?


YES - Repair short in the wire between the ECM/PCM (A21) and the MAP sensor, the APP sensor or the output shaft (countershaft) 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 goes away with a known-good ECM/PCM, replace the original ECM/PCM.n


81.Measure voltage between body ground and ECM/PCM connector terminal 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.n


NO - Go to 82.

82.Turn the ignition switch OFF.

83.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
  • Input shaft (mainshaft) speed sensor (A/T)

 

Is there about 5 V?


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


NO - Go to 84.


84.Turn the ignition switch OFF.

85.Jump the SCS line with the HDS.

86.Disconnect the connector from the following sensors.

  • Accelerator pedal position (APP) sensor
  • Input shaft (mainshaft) speed sensor (A/T)

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

88.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 or input shaft (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 goes away with a known-good ECM/PCM, replace the original ECM/PCM.n