Diagnostic Aids

WARNING: This page is about a different variant/trim than selected.

Perform this test when instructed during QUICK TEST or if directed by other test procedures. This test is used to diagnose the following:

Fuel shutoff valve relay.
Inertia Fuel Shutoff (IFS) switch.
Wiring harness circuits (B+, FSV, FSVM, Ground, POWER-TO-FUEL SHUTOFF VALVE and VPWR).
Powertrain Control Module (PCM).

Fig 1: Typical Fuel Pump Relay Schematic

Fig 2: Fuel Shutoff System Test Circuit & Connector Terminals
1. 1) KOEO & KOER DTC P0230 Fuel shutoff valve primary circuit has been indicated. Possible causes are as follows:
  - Open or shorted circuit.
  - Faulty fuel shutoff valve relay.
  - Faulty PCM.
  For Continuous Memory DTC P0230, go to step 40). Disconnect fuel shutoff valve relay wiring harness connector. Turn ignition on. Measure voltage between VPWR terminal at connector and chassis ground. If 10.5 volts or more are present, go to next step. If less than 10.5 volts are present, repair open in VPWR circuit between EEC power relay and fuel shutoff valve relay.
2. 2) Check Fuel Shutoff Valve Relay Turn ignition off. Leave fuel shutoff valve relay disconnected. Measure resistance between terminals No. 85 and 86 at fuel shutoff valve relay. Resistance should be 40-120 ohms. Measure resistance between terminals No. 30 and 87 at fuel shutoff valve relay. Resistance should be more than 10,000 ohms. If resistance is not as specified, replace fuel shutoff valve relay. If resistance is as specified, go to next step.
3. 3) Check Fuel Shutoff Valve Circuit Leave ignition off and fuel shutoff valve relay disconnected. Disconnect PCM wiring harness connector. Inspect pins for damage and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Turn ignition on. Measure voltage between test pin No. 80 (FSV) and chassis ground. If voltage is one volt or less, go to next step. If voltage is more than one volt, repair short to power in FSV circuit and repeat QUICK TEST .
4. 4) Leave ignition off and fuel shutoff valve relay disconnected. Disconnect scan tester from Data Link Connector (DLC). Measure resistance between test pin No. 80 (FSV) and test pins No. 51, 103 (PWR GND) and 91 (SIG RTN). If each resistance measurement is more than 10,000 ohms, go to next step. If any resistance measurement is 10,000 ohms or less, repair short circuit and repeat QUICK TEST .
5. 5) Leave ignition off and fuel shutoff valve relay disconnected. Measure resistance between FSV terminal at fuel shutoff valve relay wiring harness connector and test pin No. 80 at breakout box. If resistance is less than 5 ohms and DTC P0231 or P0232 is present with DTC 230, go to next step. If resistance less than 5 ohms and specified DTCs are not present, replace PCM and repeat QUICK TEST . If resistance 5 ohms or more, repair open circuit, repeat QUICK TEST .
6. 6) Check PCM Fuel Shutoff Valve Circuit Leave ignition off. Remove breakout box. Reconnect PCM and fuel shutoff valve relay. Connect scan tester to DLC. Turn ignition on. Using scan tester, access FSV PID. If scan tester indicates YES, replace PCM and repeat QUICK TEST . If scan tester does not indicate YES, go to next step.
7. 7) Leave scan tester accessed to FSV PID. Using starter, crank engine. If scan tester indicates YES during crank, replace PCM and repeat QUICK TEST . If scan tester does not indicate YES during crank, fuel shutoff valve primary circuit is okay. If DTC P0231 is present, go to step 20). If DTC P0232 is present, go to step 10).
  NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 7) to step 10). No test procedures have been omitted.
8. 10) KOEO & KOER DTC P0232 If engine starts, go to next step. If engine does not start, go to step 15). For Continuous Memory DTC P0232, go to step 30).
9. 11) Check Power To Fuel Shutoff Valve Turn ignition and all accessories off. Disconnect scan tester from DLC (if applicable). Disconnect PCM wiring harness connector. Inspect pins for damage and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Turn ignition on. Measure voltage between test pin No. 40 (FSVM) and 51 (PWR GND) at breakout box. If voltage is more than 1.5 volts, go to next step. If voltage is 1.5 volts or less, go to step 13).
10. 12) Check Fuel Shutoff Valve Relay Turn ignition off. Disconnect fuel shutoff valve relay. Turn ignition on. Measure voltage between test pin No. 40 (FSVM) and 51 (PWR GND) at breakout box. If voltage is less than 1.5 volts, replace fuel shutoff valve relay and repeat QUICK TEST . If voltage is 1.5 volts or more, repair short to power in FSVM or POWER-TO-FUEL SHUTOFF VALVE circuit and repeat QUICK TEST .
11. 13) Check FSVM Circuit Turn ignition off. Leave fuel shutoff valve relay disconnected. Measure resistance between test pin No. 40 and POWER-TO-FUEL SHUTOFF VALVE circuit at fuel pump relay wiring harness connector. If resistance is less than 5 ohms, replace PCM and repeat QUICK TEST . If resistance is 5 ohms or more, repair open circuit and repeat QUICK TEST .
12. 14) Check IFS Switch Turn ignition off. Locate IFS switch in trunk near left hinge. Measure resistance between terminals "C" and NC of IFS switch. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, reset or replace IFS switch and repeat QUICK TEST .
13. 15) Check Circuit Continuity Leave ignition off, IFS switch and fuel shutoff valve relay disconnected. Measure resistance of POWER-TO-FUEL SHUTOFF VALVE circuit between fuel shutoff valve relay connector and IFS connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in POWER-TO-FUEL SHUTOFF VALVE circuit and repeat QUICK TEST .
14. 16) Leave ignition off, fuel shutoff valve relay and IFS switch disconnected. Measure resistance between POWER-TO-FUEL SHUTOFF VALVE circuit at IFS connector and chassis ground. If resistance is less than 10 ohms, fault cannot be located and testing is complete. If resistance 10 ohms or more, repair open circuit and repeat QUICK TEST .
  NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 16) to step 20). No test procedures have been omitted.
15. 20) DTC P0231 If engine starts, replace PCM and repeat QUICK TEST . If engine does not start, go to next step. For Continuous Memory DTC P0231, go to step 35).
16. 21) Check B+ To Fuel Shutoff Valve Relay Turn ignition off. Disconnect fuel shutoff valve relay wiring harness connector. Measure voltage between chassis ground and B+ terminal at wiring harness connector. If voltage is 10.5 volts or more, go to next step. If voltage is less than 10.5 volts, check circuit fuse. If fuse is okay, repair open in B+ circuit and repeat QUICK TEST .
17. 22) Check POWER-TO-FUEL SHUTOFF VALVES Circuit Continuity Leave ignition off and fuel shutoff valve relay disconnected. Measure resistance between negative battery terminal and POWER-TO-FUEL SHUTOFF VALVES terminal at harness connector. If resistance less than 10 ohms, replace fuel shutoff valve relay, repeat QUICK TEST . If resistance is 10 ohms or more, repair open in POWER-TO-FUEL SHUTOFF VALVES circuit and repeat QUICK TEST .
  NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 22) to step 30). No test procedures have been omitted.
18. 30) Continuous Memory DTC P0232 Turn ignition off. Connect scan tester to Data Link Connector (DLC). Using scan tester, access FSVM PID. Observe PID for indication of fault while wiggling and bending POWER-TO-FUEL SHUTOFF VALVES circuit. Fault will be indicated by FSVM PID turning on. Wiggle and bend fuel shutoff valve ground circuit. Check connectors for clean tight connection. If any faults are found, isolate and repair as necessary. If no faults are found, fault cannot be duplicated at this time. Go to CIRCUIT TEST Z.
  NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 30) to step 35). No test procedures have been omitted.
19. 35) Continuous Memory DTC P0231 Turn ignition off. Disconnect PCM wiring harness connector. Inspect pins for damage and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Connect jumper wire between test pins No. 77 (PWR GND) and 80 (FSV). Connect DVOM between test pins No. 40 (FSVM) and 51 (PWR GND). Voltage should be 10 volts or more. Observe DVOM for indication of fault while wiggling and bending B+ circuit to fuel shutoff valve relay. Fault will be indicated by sudden change in DVOM voltage. Wiggle and bend POWER-TO-FUEL SHUTOFF VALVES circuit between fuel shutoff valve relay and FSVM circuit splice. Lightly tap on fuel shutoff valve relay. Check connectors for clean tight connection. If any faults are found, isolate and repair as necessary. If no faults are found, fault cannot be duplicated at this time. Go to CIRCUIT TEST Z.
  NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 35) to step 40). No test procedures have been omitted.
20. 40) Continuous Memory DTC P0230 Turn ignition off. Connect scan tester to Data Link Connector. Turn ignition on and wait 5 seconds. Using scan tester, access FSVF PID. Observe PID for indication of fault while wiggling and bending FUEL shutoff valve circuit between fuel shutoff valve relay and PCM. Fault will be indicated if FSVF PID switches to YES. Wiggle and bend FSV circuit between PCM and fuel shutoff valve relay. Wiggle and bend VPWR circuit between fuel shutoff valve relay and EEC-V power relay. Check connectors for clean tight connection. If any faults are found, isolate and repair as necessary. If no faults are found, fault cannot be duplicated at this time. Go to CIRCUIT TEST Z.