(DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Special Tools
J 43244 Relay Puller Pliers
Circuit/System Verification
Important: An open or a short to voltage in the control circuit will cause both the Ckt. Open Test Status and the Ckt. Short Volts Test
Status parameters to display Fault.
Ignition ON, command the fuel pump relay ON and OFF with a scan tool while observing the following control circuit status parameters:
* Fuel Pump Relay Ckt. Short Gnd Test Status
* Fuel Pump Relay Ckt. Open Test Status
* Fuel Pump Relay Ckt. Short Volts Test Status
Each parameter should toggle between OK and Not Run or Not Run and OK.
Circuit/System Testing
1. Ignition OFF, disconnect the fuel pump relay.
2. Ignition ON, verify that a test lamp illuminates between the ground circuit terminal 85 and B+.
锟斤拷If the test lamp does not illuminate, test the ground circuit for a short to voltage or an open/high resistance.
3. Verify that a test lamp does not illuminate between the ground circuit terminal 85 and the control circuit terminal 86.
锟斤拷If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Remove the test lamp.
5. Command the fuel pump relay ON with a scan tool. Verify the scan tool fuel pump relay Ckt. Short Grnd Test Status parameter is OK.
锟斤拷If not the specified value, test the fuel pump relay control circuit for a short to ground. If the circuit tests normal, replace the ECM.
6. Install a 3A fused jumper wire between the fuel pump relay control circuit terminal 86 and the ground circuit terminal 85. Command the fuel
pump ON with a scan tool. Verify the scan tool fuel pump relay Ckt. Short Grnd Test Status parameter is Fault.
锟斤拷If not the specified value, test the fuel pump relay control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
7. Inspect the fuel pump fuse.
锟斤拷If the fuel pump fuse is open, test for the following conditions:
* A short to ground in the relay switch B+ circuit
* A short to ground in the supply voltage circuit of the fuel pump
锟斤拷If the above circuits test normal, replace the fuel tank module.
8. Verify that a test light illuminates between the B+ circuit and ground.
锟斤拷If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.
9. Connect a 15A fused jumper wire between the B+ circuit and the supply voltage circuit of the fuel pump. Verify the fuel pump is activated.
锟斤拷If the fuel pump does not activate, test for the following conditions:
* An open/high resistance in the supply voltage circuit of the fuel pump
* An open/high resistance in the ground circuit of the fuel pump
锟斤拷If the above circuits test normal, replace the fuel tank module.
10. If all circuits test normal, test or replace the fuel pump relay.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
