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Home >> Mazda >> 2001 >> B2500 SE, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> System Tests >> Test KA: Fuel Pump Relay >> Diagnostic Aids

Diagnostic Aids

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

  1. 1) KOEO & KOER DTC P0230: Check VPWR Voltage To Fuel Pump Relay

    This DTC indicates a fuel pump primary circuit failure. Possible causes are:
    • Open Or Shorted Fuel Pump (FP) Circuit
    • Open VPWR Circuit To Fuel Pump Relay
    • Faulty Fuel Pump Relay
    • Faulty PCM

    Remove fuel pump relay from battery junction box in engine compartment. Turn ignition switch to ON position. Using a DVOM, measure voltage between fuel pump relay connector VPWR cavity and negative battery terminal. See Fig 1 or Fig 2 . If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open in VPWR circuit between PCM power relay and fuel pump relay.

    Fig 1: Identifying Fuel System Circuits & Connector Terminals (Except Tribute)
    G00035631Courtesy of FORD MOTOR CO.
    Fig 2: Identifying Fuel System Circuits (Tribute)
    G99A02631Courtesy of FORD MOTOR CO.
    2. NOTE: To identify fuel pump relay terminals, refer to numbers molded on relay. Two different numbered relays are used. Fuel pump relay terminals may be numbered 1-5 or terminals may be numbered 30, 85, 86, 87 and 87A. On relays that are numbered 1-5, terminals for relay coil are terminals No. 1 and 2. On relays that are numbered 30, 85, 86, 87 and 87A, terminals for relay coil are terminals No. 85 and 86.

  2. 2) Check Fuel Pump Relay
    Turn ignition switch to OFF position. On ISO micro fuel pump relays that terminals are numbered 1-5, measure resistance between relay terminal No. 1 and all other relay terminals. Resistance should be 40-120 ohms between terminals No. 1 and 2 and more than 10 k/ohms between terminal No. 1 and all other relay terminals. On ISO mini fuel pump relays that terminals are numbered 30, 85, 86, 87 and 87A, measure resistance between relay terminal No. 85 and all other relay terminals. Resistance should be 40-120 ohms between terminals No. 85 and 86 and more than 10 k/ohms between terminal No. 85 and other relay terminals. On both relays, if resistance is not as specified replace relay. If resistance is as specified, go to next step.

  3. 3) Check Fuel Pump (FP) Circuit For Short To VPWR In Harness

    Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. Using a DVOM, measure voltage between ground and PCM harness connector FP circuit terminal. See Fig 1 or Fig 2 . If voltage is less than one volt, go to next step. If voltage is one volt or more, repair short to VPWR in FP circuit.

  4. 4) Check FP Circuit For Short To Ground In Harness

    Turn ignition switch to OFF position. Disconnect scan tool from Data Link Connector (DLC). Using a DVOM, measure resistance between ground and PCM harness connector FP circuit terminal. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in FP circuit.

  5. 5) Check FP Circuit For Open In Harness

    Using a DVOM, measure resistance of FP circuit between fuel pump relay harness connector and PCM harness connector. If resistance is less than 5 ohms and KOEO DTC P0231 or P0232 is also present with DTC P0230, go to next step. If resistance is less than 5 ohms and KOEO DTC P0231 or P0232 is not present with DTC P0230, replace PCM. If resistance is 5 ohms or more, repair open in FP circuit.

  6. 6) Check Fuel Pump Primary Circuit Inside PCM

    Reconnect PCM harness connector and fuel pump relay. Connect scan tool to DLC. Turn ignition switch to ON position. Using scan tool, select FPF PID from PID/DATA MONITOR & RECORD menu. If FPF PID value indicates YES, a fault exists inside of PCM. Replace PCM. If FPF PID value indicates NO, go to next step.

  7. 7) Check Fuel Pump Primary Circuit Inside PCM While Cranking Engine

    Ensure battery is fully charged. To perform this step, ensure scan tool is connected to a power source that is powered with key in START position. While cranking engine, observe FPF PID value. If FPF PID value indicates YES during cranking, replace PCM. If FPF PID value indicates NO during cranking, fuel pump primary circuit is okay in harness and PCM. 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: Check Engine For Start

    This DTC indicates that PCM detected high FPM circuit voltage when fuel pump was commanded off. Possible causes are:
    • Inertia Fuel Shutoff (IFS) Switch Open Or Not Reset
    • Open Circuit Between Fuel Pump & FPM Connection To FP PWR Circuit
    • Poor Fuel Pump Ground
    • Fuel Pump Internal Open
    • Fuel Pump Secondary Circuits Shorted To VPWR
    • Fuel Pump Relay Contacts Always Closed
    • Open FPM Circuit Between PCM & Connection To FP PWR Circuit
    • Faulty PCM (Engine Will Start)

    Attempt to start engine. If engine starts, go to next step. If engine does not start, go to step  15).

  9. 11) Verify That Fuel Pump Is Off

    Turn ignition switch to ON position and wait 5 seconds. Listen for operational noise from fuel pump (listen near fuel tank if necessary). If fuel pump operates with ignition switch turned to ON position, go to next step. If fuel pump does not operate with ignition switch turned to ON position, go to step  13).

  10. 12) Check For Fuel Pump Relay Always Closed

    Turn ignition switch to OFF position. Remove fuel pump relay from battery junction box in engine compartment. Turn ignition switch to ON position. Listen for operational noise from fuel pump. If fuel pump operates, repair short to VPWR in FP PWR or FPM circuit. If fuel pump does not operate, replace fuel pump relay.

  11. 13) Check For Open FPM Circuit

    Turn ignition switch to OFF position. Remove fuel pump relay from battery junction box in engine compartment. Disconnect PCM connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of FPM circuit between PCM harness connector and fuel pump relay harness connectorl. See Fig 1 or Fig 2 . If resistance is less than 5 ohms for DTC P0231, replace PCM. If resistance is less than 5 ohms for DTC P0232, go to next step. If resistance is 5 ohms or more for either DTC, repair open in FPM circuit.

  12. 14) Check FPM Circuit In PCM

    Reconnect PCM harness connector and fuel pump relay. Turn ignition switch to ON position. Using scan tool, select FP M PID from PID/DATA MONITOR & RECORD menu. On all models, if FP M PID value indicates ON, replace PCM. If FP M PID value indicates OFF, no problem is indicated at this time. Fuel pump primary circuit is okay in harness and PCM. Testing is complete. Disregard DTC P0232 at this time. Repeat QUICK TEST .

  13. 15) Check IFS Switch

    Turn ignition switch to OFF position. Disconnect IFS switch connector. Ensure IFS switch is reset. Using a DVOM, measure resistance between IFS switch Dark Green/Yellow and Pink/Black wire terminals. If resistance is less than 5 ohms between appropriate terminals, go to next step. If resistance is 5 ohms or more between appropriate terminals, reset or replace IFS switch as necessary.

  14. 16) Check For Open FP PWR Circuit Between IFS Switch & Fuel Pump Relay

    Remove fuel pump relay battery junction box in engine compartment. Using a DVOM, measure resistance of FP PWR circuit between fuel pump relay harness connector and IFS switch harness connector. See Fig 1 or Fig 2 . If resistance is less than 5 ohms, reconnect fuel pump relay and go to next step. If resistance is 5 ohms or more, repair open in FP PWR circuit.

  15. 17) Check For Open Fuel Pump Ground Circuit

    Disconnect fuel pump connector. Using a DVOM, measure resistance of fuel pump ground circuit between ground and fuel pump harness connector. See WIRING DIAGRAMS article. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in fuel pump ground circuit.

  16. 18) Check For Open FP PWR Circuit Between IFS Switch & Fuel Pump

    Using a DVOM, measure resistance of FP PWR circuit between fuel pump harness connector and IFS switch harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in FP PWR circuit.

  17. 19) Check Internal Resistance Of Fuel Pump

    Using a DVOM, measure resistance between fuel pump FP PWR and ground terminals. If resistance is 10 ohms or more, replace fuel pump. If resistance is less than 10 ohms, fuel pump circuits are okay. Testing is complete. Disregard DTC P0232 at this time. Repeat QUICK TEST .

  18. 20) KOEO & KOER DTC P0231: Check Engine For Start

    This DTC indicates PCM commanded fuel pump ON and B+ voltage is not detected on Fuel Pump Monitor (FPM) circuit. Possible causes are:
    • Open B+ Circuit To Fuel Pump Relay
    • Open FP PWR Circuit Between Fuel Pump Relay & Connection To FPM Circuit
    • Faulty Fuel Pump Relay
    • Faulty PCM (Engine Will Start)

    If KOEO DTC P0231 is also present and has not been diagnosed, primary fuel pump circuits must be checked first. Go to step  1). Attempt to start engine. If engine starts, go to step  13). If engine does not start, go to next step.

  19. 21) Check For B+ Voltage To Fuel Pump Relay

    Turn ignition switch to OFF position. Remove fuel pump relay from battery junction box in engine compartment. Using a DVOM, measure voltage between ground and fuel pump relay harness connector B+ terminal. See Fig 1 or Fig 2 . If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, check condition of related fuses/fuse links. If fuse/fuse links are blown, check for short to ground in B+ or FP PWR circuit. Repair as necessary. If fuse/fuse links are okay, repair open in B+ circuit.

  20. 22) Check For Open FP PWR Circuit Between Fuel Pump Relay & FPM Splice

    Using a DVOM, measure resistance between negative battery terminal and fuel pump relay harness connector FP PWR circuit terminal. If resistance is less than 10 ohms, replace fuel pump relay. If resistance is 10 ohms or more, repair open in FP PWR circuit between fuel pump relay and FPM splice.

  21. 23) Check VPWR & IFS Circuits To IFS Switch Relay (F150 Lightning 5.4L SC)

    Remove IFS switch relay from battery junction relay box in engine compartment. Turn ignition switch to ON position. Using a DVOM, measure voltage between IFS switch relay harness connector VPWR circuit and IFS circuit terminals. If voltage is more than 10.5 volts, turn ignition switch to OFF positionand go to step  28). If voltage is 10.5 volts or less, go to next step.

  22. 24) Check For VPWR To IFS Switch Relay

    Using a DVOM, measure voltage between ground and IFS switch relay harness connector VPWR circuit terminal. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, check for blown battery junction box fuse No. 10 (15-amp). If fuse is blown, check for short to ground in VPWR circuit. If fuse is okay, check for open in VPWR circuit between battery junction box and IFS switch relay. See WIRING DIAGRAMS article.

  23. 25) Check Ground Circuit To IFS Switch

    Turn ignition switch to OFF position. Disconnect Inertia Fuel Shutoff (IFS) switch connector. Ensure IFS switch is reset. Using a DVOM, measure resistance of ground circuit between ground and IFS switch harness connector ground circuit terminal. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in ground circuit.

  24. 26) Check IFS Switch

    Using a DVOM, measure resistance between IFS switch Dark Green/Yellow and Pink/Black wire terminals. If resistance is less than 5 ohms between terminals, go to next step. If resistance is 5 ohms or more between terminals, reset or replace IFS switch as necessary.

  25. 27) Check For Open IFS Circuit

    Using a DVOM, measure resistance of IFS circuit between IFS switch harness connector and IFS switch relay harness connector. If resistance is 5 ohms or more, repair open in IFS circuit. If resistance is less than 5 ohms, no fault is indicated. Disregard DTC P0232 at this time. Repeat QUICK TEST .

  26. 28) Check FP PWR Circuit Continuity Between Fuel Pump Relay & IFS Switch Relay

    Using a DVOM, measure resistance of FP PWR circuit between fuel pump relay harness connector and IFS switch relay harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in FP PWR circuit.
    27. NOTE: To identify IFS switch relay terminals, refer to numbers molded on relay.
    Fig 3: Identifying ISO Mini Relay Terminals
    G97D28186Courtesy of FORD MOTOR CO.

  27. 29) Check Operation Of IFS Switch Relay & Fuel Pump Relay
    Connect a jumper wire between positive battery terminal and IFS switch relay terminal No. 86. Connect another jumper wire between negative battery terminal and IFS switch relay terminal No. 85. See Fig 3. With relay energized, measure resistance between terminals No. 30 and 87 at IFS switch relay. Resistance should be less than 5 ohms. Repeat test for fuel pump relay. Replace appropriate relay as necessary. If relays are okay, repair open in FP PWR circuit between FPM splice and IFS switch relay. See WIRING DIAGRAMS article.
    28. NOTE: DTC P0232 can be set if Inertia Fuel Shutoff (IFS) switch is tripped then reset, or if VPWR was supplied to FP PWR circuit when PCM expected fuel pump to be OFF.
    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.

  28. 30) Continuous Memory DTC P0232: Check Fuel Pump Secondary Circuits
    If continuous memory DTC P0230 is also present, go to step  40). If continuous memory DTC P0232 is only DTC present, turn ignition switch to ON position. Using scan tool, select FP M PID from PID/DATA MONITOR & RECORD menu. Observe FP M PID value for indication of fault while wiggling and bending FP PWR circuit between fuel pump relay and fuel pump. A fault (an open or short to VPWR) will be indicated by FP M PID value changing to ON. Wiggle and bend FPM circuit between PCM and FP PWR circuit splice. Wiggle and bend fuel pump ground circuit from fuel pump to ground. Lightly tap on fuel pump, IFS switch and fuel pump relay to simulate road shock. On F150 Lightning 5.4L SC, remove low speed fuel pump relay and note FP M PID. On all models, check connectors for clean tight connection. If no faults are found (FP M PID value remains OFF), fault cannot be duplicated at this time. Go to TEST Z, step  1). If any fault is found, isolate fault and repair as necessary.

  29. 35) Continuous Memory DTC P0231: Check Harness Circuits

    This DTC indicates that sometime during vehicle operation when fuel pump was commanded on, FPM circuit voltage was low. Possible causes are:
    • Open B+ Circuit To Fuel Pump Relay
    • Open FP PWR Circuit Between Fuel Pump Relay & Connection To FPM Circuit
    • Faulty Fuel Pump Relay
    • Faulty PCM (Engine Will Start)

    Turn ignition switch to OFF position. Disconnect PCM connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Connect a jumper wire between PCM harness connector FP circuit terminal and ground. See Figure,Fig 1 or Fig 2 . Connect DVOM between ground and PCM harness connector FPM circuit terminal. Turn ignition switch to ON position. Fuel pump should turn on and voltage reading on DVOM should be more than 10 volts. Observe DVOM for indication of fault while wiggling and bending B+ circuit to fuel pump relay. Fault will be indicated by sudden change in DVOM voltage. Wiggle and bend FP PWR circuit between fuel pump relay and FPM circuit splice. Lightly tap on fuel pump relay to simulate road shock. On F150 Lightning 5.4L SC, shake, wiggle and bend circuits connected to Inertia Fuel Shutoff (IFS) switch relay. Lightly tap on IFS switch and IFS switch relay. On all models, check connectors for clean tight connection. If any faults are found, isolate fault and repair as necessary. If no faults are found, fault cannot be duplicated at this time. Go to TEST Z, step  1).

    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.

  30. 40) Continuous Memory DTC P0230: Check Fuel Pump Primary Circuits

    This DTC indicates a fuel pump primary circuit fault. Possible causes are:
    • Open Or Shorted Fuel Pump (FP) Circuit
    • Open VPWR Circuit To Fuel Pump Relay
    • Faulty Fuel Pump Relay
    • Faulty PCM

    Turn ignition switch to ON position and wait 5 seconds. Using scan tool, select FPF PID from PID/DATA MONITOR & RECORD menu. FPF PID value should indicate NO, indicating PCM detects VPWR voltage through fuel pump relay coil and Fuel Pump (FP) circuit. Observe FPF PID value for indication of fault while wiggling and bending FP circuit between fuel pump relay and PCM. FPF PID will read YES, when a fault is indicated. Wiggle and bend VPWR circuit between fuel pump relay and PCM power relay. Lightly tap on fuel pump relay to simulate road shock. 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 TEST Z, step  1).

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 40) to step 45). No test procedures have been omitted.

  31. 45) KOEO Or KOER DTC P1232: Check VPWR To Low Speed Fuel Pump Relay

    This DTC indicates a low speed fuel pump primary circuit fault. Possible causes are:
    • Open Or Shorted Low Speed Fuel Pump (LFP) Circuit
    • Open VPWR To LFP Relay
    • Faulty LFP Relay
    • Faulty PCM

    Turn ignition switch to OFF position. Remove low speed fuel pump relay from battery junction relay box located in engine compartment. Turn ignition switch to ON position. Using a DVOM, measure voltage of VPWR circuit between ground and low speed fuel pump relay VPWR cavity. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open in VPWR circuit between PCM power relay and low speed fuel pump relay.

    32. NOTE: To identify fuel pump relay terminals, refer to numbers molded on relay.

  32. 46) Check Low Speed Fuel Pump Relay
    Turn ignition switch to OFF position. Using a DVOM, measure resistance between LFP relay terminal No. 85 and all other LFP relay terminals. See Fig 3. Resistance between LFP relay terminals No. 85 and 86 should be 40-100 ohms. Resistance between LFP relay terminal No. 85 and all other terminals should be more than 10 k/ohms. If any resistance measurement is not as specified, replace LFP relay. If all resistance measurements are as specified, go to next step.

  33. 47) Check Low Fuel Pump Circuit For Short To VPWR In Harness

    Ensure ignition switch is turned to OFF position. Disconnect PCM connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. Using a DVOM, measure voltage of LFP circuit between ground and LFP relay cavity. If voltage is less than one volt, go to next step. If voltage is one volt or more, repair short to VPWR in LFP circuit.

  34. 48) Check LFP Circuit For Short To Ground In Harness

    Turn ignition switch to OFF position. Disconnect scan tool from Data Link Connector (DLC). Using a DVOM, measure resistance between ground and LFP cavity at LFP relay. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in LFP circuit.

  35. 49) Check For Open LFP Circuit

    Using a DVOM, measure resistance of LFP circuit between PCM harness connector and LFP relay cavity. If resistance is less than 5 ohms, replace PCM. If resistance is 5 ohms or more, repair open in LFP circuit.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 49) to step 55). No test procedures have been omitted.

  36. 55) Check For Open Fuel Pump Ground Circuit Through Resistor

    Turn ignition switch to OFF position. Remove low speed fuel pump relay from battery junction relay box located in engine compartment. Turn ignition switch to ON position. Using scan tool, select FP M PID from PID/DATA MONITOR & RECORD menu. If FP M PID value indicates OFF, no fault is indicated at this time. Disregard DTC P0232 at this time. Repeat QUICK TEST . If FP M PID value indicates ON, check fuel pump relay ground circuit resistor. Replace resistor as necessary. If resistor is okay, repair open circuit between LFP relay and wiring harness splice.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 55) to step 60). No test procedures have been omitted.

  37. 60) Continuous Memory DTC P1232: Check Low Speed Fuel Pump Primary Circuits

    This DTC indicates a low speed fuel pump primary circuit fault. Possible causes are:
    • Open Or Shorted Low Speed Fuel Pump (LFP) Circuit
    • Open VPWR To LFP Relay
    • Faulty LFP Relay
    • Faulty PCM

    Turn ignition switch to ON position and wait 5 seconds. Using scan tool, select LFPF PID from PID/DATA MONITOR & RECORD menu. LFPF PID value should indicate NO (indicating PCM detects VPWR voltage through LFP relay coil and LFP circuit). Observe LFPF PID value for indication of fault while wiggling and bending LPF circuit between LFP relay and PCM harness connector. Fault will be indicated by LFPF PID indicating YES. Wiggle and bend VPWR circuit between LFP relay and PCM power relay. Lightly tap on LFP relay to simulate road shock. Check connectors for clean tight connection. If any faults are found, isolate fault and repair as necessary. If no faults are found, fault cannot be duplicated at this time. Go to TEST Z, step  1).

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 60) to step 65). No test procedures have been omitted.

  38. 65) Check Resistance Of Fuel Pump Ground Circuit Through Resistance

    Turn ignition switch to OFF position. Remove low speed fuel pump relay from battery junction relay box located in engine compartment. Using a DVOM, measure resistance of ground circuit through resistor between LFP relay cavity No. 30 and ground. See Fig 3. If resistance is less than 7 ohms, go to next step. If resistance is 7 ohms or more, check LFP relay ground circuit resistor. Replace resistor as necessary. If resistor is okay, repair open in ground circuit.

  39. 66) Check For Open In Ground Circuit Between LFP Relay & Fuel Pumps

    Ensure ignition switch is turned to OFF position. Disconnect fuel pump connectors. Using a DVOM, measure resistance of ground circuit between LFP relay cavity No. 30 and one of the fuel pump harness connectors. Repeat resistance measurement for ground circuit in other fuel pump wiring harness. If both resistance measurements are less than 5 ohms, go to next step. If either resistance measurement is 5 ohms or more, repair open in appropriate ground circuit.

  40. 67) Check Internal Resistance Of Each Fuel Pump

    Ensure ignition switch is turned to OFF position. Using a DVOM, measure resistance between both fuel pump terminals. Resistance should be less than 10 ohms. Repeat resistance check for other fuel pump. If either fuel pump resistance measurement is not within specification, replace faulty fuel pump(s) as necessary. If both fuel pump resistance measurements are within specification, go to next step.

  41. 68) Check For Open In FP PWR Circuit Between FPM Splice & Fuel Pumps

    Ensure ignition switch is turned to OFF position. Remove Inertia Fuel Shutoff (IFS) switch relay from battery junction relay box located in engine compartment. Using a DVOM, measure resistance of FP PWR circuit between IFS switch relay cavity No. 87 and one of the fuel pumps harness connector. Repeat resistance check for other fuel pump. If both resistance measurements are less than 5 ohms, no fault is indicated. Disregard DTC P0232 at this time. Repeat QUICK TEST . If either resistance measurement is 5 ohms or more, repair open in FP PWR circuit between fuel pump and FPM circuit splice to PCM.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 68) to step 70). No test procedures have been omitted.
    NOTE: Diagnostic steps  70)- 72) are performed when directed here from SYMPTOMS in TROUBLE SHOOTING - NO CODES article.

  42. 70) Hard Start/Lacks Power: Check High Speed Fuel Pump Ground Circuit Between Low Speed Fuel Pump Relay & Chassis Ground

    Turn ignition switch to OFF position. Remove low speed fuel pump relay from battery junction relay box located in engine compartment. Using a DVOM, measure resistance of ground circuit between LFP relay cavity No. 87A and ground. See Fig 3. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in ground circuit.

  43. 71) Check Ground Circuit Through Resistor

    Ensure ignition switch is turned to OFF position. Using a DVOM, measure resistance of ground circuit through resistor between LFP relay cavity No. 30 and ground. See Fig 3. If resistance is less than 7 ohms, go to next step. If resistance is 7 ohms or more, check LFP relay ground circuit resistor. Replace resistor as necessary. If resistor is okay, repair open in ground circuit.

  44. 72) Check Normally Closed Contacts Of LFP Relay

    Using a DVOM, measure resistance between LFP relay terminals No. 30 and 87A. See Fig 3. If resistance is less than 5 ohms, high speed fuel pump circuits are okay. If symptom still exists, return to SYMPTOMS in TROUBLE SHOOTING - NO CODES article. If resistance is 5 ohms or more, replace LFP relay.
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