Circuit/System Testing

Engine Control Module

1. Ignition OFF, disconnect the harness connectors at the K20 ECM.
2. Ignition OFF, and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 Ω between the ground circuit terminals listed below and ground:
   • Terminal 73 X2 (LAF or LFW)
   • Terminal 73 X3 (LAF or LFW)
   • If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a 15 A fused jumper wire between B+ and the KR71 engine control module relay switch control terminal 87. Ignition ON, verify that a test lamp illuminates between the IGN/B+ circuit terminals listed below and ground:
   • Terminal 51 X1 (LAF or LFW)
   • Terminal 52 X1 (LAF or LFW)
   • Terminal 73 X1 (LAF or LFW)
   • If the test lamp does not illuminate, test the IGN/B+ circuit for a short to ground or an open/high resistance.
4. If all circuits test normal, replace the K20 ECM.

Fuel Pump Control Module

1. Ignition OFF, disconnect the harness connectors at the K27 fuel pump control module.
2. Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 Ω between the ground circuit terminal 25 and ground.
   • If greater than the specified range, test the ground circuit for an open/high resistance.
3. Verify that a test lamp illuminates between the IGN/B+ circuit terminals listed below and ground:
   • Terminal 1
   • Terminal 21
   • If the test lamp does not illuminate, test the IGN/B+ circuit for a short to ground or an open/high resistance.
4. If all circuits test normal, replace the K27 fuel pump control module.

Transmission Control Module

1. Ignition OFF, disconnect the harness connectors at the T12 transmission.
2. Ignition OFF, and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 Ω between the ground circuit terminals listed below and ground:
   • Terminal 1 (MH2/MH4)
   • Terminal 18 (MH2/MH4)
   • Terminal 2 (MH7/MHC)
   • If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the IGN/B+ circuit terminals listed below and ground:
   • Terminal 10 (MH2/MH4)
   • Terminal 13 (MH2/MH4)
   • Terminal 1 (MH7/MHC)
   • Terminal 12 (MH7/MHC)
   • If the test lamp does not illuminate, test the IGN/B+ circuit for a short to ground or an open/high resistance.
4. If all circuits test normal, replace the K71 transmission control module.