Test Procedure
WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
- KB1 DIAGNOSTIC TROUBLE CODES (DTCS) P1233, P1235, AND P1237: CHECK FOR SELF-TEST DTCS
- Are any of the following DTCs present during PCM or transaxle control module (TCM) self-test: P1233, P1235, or P1237?
Yes No For DTC P1233, GO to KB2.
For DTC P1235, GO to KB17.
For DTC P1237, GO to KB25.RETURN to the SYMPTOM CHARTS article, Symptom Charts for further direction. - KB2 DTC P1233: IS DTC P1233 PRESENT IN THE KOEO SELF-TEST?
- Is DTC P1233 present in the KOEO or KOER self-test?
Yes No GO to KB4. The PCM is now receiving a signal from the FPDM. One possible cause of DTC P1233 is that the IFS switch was tripped, then reset.
GO to KB3. - KB3 DOES THE ENGINE START?
- Does the engine start?
Yes No GO to KB13. DISREGARD the DTC at this time. RETURN to Section 3 and continue as directed. After repairing the no start, to diagnose intermittent causes of P1233,
GO to KB13. - KB4 KOEO DTC P1233: DOES THE ENGINE START?
- Does the engine start?
Yes No To check the FPM circuit,
GO to KB9.VERIFY the IFS switch is set (button pressed).
GO to KB5. - KB5 CHECK THE VOLTAGE AND GROUND CIRCUITS TO THE FPDM
- FPDM connector disconnected.
- Key ON, engine OFF.
- Measure the voltage between:
( + ) FPDM Connector, Harness Side ( - ) FPDM Connector, Harness Side VPWR - Pin 5 GND - Pin 3 - Is the voltage greater than 10.5 V?
Yes No INSTALL a new FPDM. REFER to FUEL CHARGING AND CONTROLS - HYBRID .
CLEAR the DTCs. REPEAT the self-test.GO to KB6. - KB6 CHECK VOLTAGE TO FPDM
- Key ON, engine OFF.
- Measure the voltage between:
( + ) FPDM Connector, Harness Side ( - ) VPWR - Pin 5 Ground - Is the voltage greater than 10.5 V?
Yes No REPAIR the open ground circuit to the FPDM.
CLEAR the DTCs. REPEAT the self-test.GO to KB7. - KB7 CHECK THE VOLTAGE TO FRONT IFS SWITCH
- Key in OFF position.
- IFS Switch connector disconnected.
- Key ON, engine OFF.
- Measure the voltage between:
( + ) IFS Switch Connector, Harness Side ( - ) VPWR - Pin 2 Ground - Is the voltage greater than 10.5 V?
Yes No GO to KB8. There is a VPWR circuit concern. CHECK the condition of the related fuse/fuse links. If OK, REPAIR the open circuit. If the fuse/fuse link is damaged, CHECK the circuit for a short to ground before installing a new fuse/fuse link.
CLEAR the DTCs. REPEAT the self-test. - KB8 CHECK THE RESISTANCE OF FRONT IFS SWITCH
- Key in OFF position.
- Measure the resistance between:
( + ) IFS Switch Connector, Component Side ( - ) IFS Switch Connector, Component Side VPWR - Pin 2 FPDMPWR-A - Pin 1 - Is the resistance less than 5 ohms?
Yes No REPAIR the open FPDM PWR circuit.
CLEAR the DTCs. REPEAT the self-test.INSTALL a new IFS switch. REFER to FUEL TANK AND LINES - HYBRID .
CLEAR the DTCs. REPEAT the self-test. - KB9 CHECK THE FPM CIRCUIT FOR AN OPEN IN THE HARNESS
- FPDM connector disconnected.
- PCM connector disconnected.
- Measure the resistance between:
( + ) FPDM Connector, Harness Side ( - ) PCM Connector, Harness Side FPM - Pin 1 FPM - Pin B46 - Is the resistance less than 5 ohms?
Yes No GO to KB10. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test. - KB10 CHECK THE FPM CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS
- Key ON, engine OFF.
- Measure the voltage between:
( + ) FPDM Connector, Harness Side ( - ) FPM - Pin 1 Ground - Is the voltage less than 1 V?
Yes No GO to KB11. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. - KB11 CHECK THE FPM CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS
- Key in OFF position.
- Measure the resistance between:
( + ) FPDM Connector, Harness Side ( - ) FPM - Pin 1 Ground - Is the resistance greater than 10K ohms?
Yes No GO to KB12. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. - KB12 CHECK FOR FPM OUTPUT FROM THE PCM NOTE: It is OK for the voltage to cycle below this range and then return within range.
- FPDM connector connected.
- Key ON, engine OFF.
- Measure the voltage between:
( + ) PCM Connector, Harness Side ( - ) FPM - Pin B46 Ground - Is the voltage between 0.02 - 1 V?
Yes No GO to KB37. INSTALL a new FPDM. REFER to FUEL CHARGING AND CONTROLS - HYBRID .
CLEAR the DTCs. REPEAT the self-test. - KB13 CHECK THE FPDM PWR AND GND CIRCUITS FOR AN INTERMITTENT CONCERN NOTE: Be aware that DTC P1233 could be set if the IFS switch is tripped then reset.
- Key in OFF position.
- FPDM connector disconnected.
- Connect a non-powered test lamp between:
( + ) FPDM Connector, Harness Side ( - ) FPDM Connector, Harness Side FPDM PWR GND - Pin 3 - Key ON, engine OFF.
- Observe the test lamp for an indication of a concern while carrying out the following. Note that the lamp turns OFF when a concern is detected.
- Wiggle, shake, and bend small sections of the wiring harness while working from the component to the module.
- Is a concern present?
Yes No ISOLATE the concern and REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.GO to KB14. - KB14 CHECK FOR AN INTERMITTENT OPEN IN THE FPM CIRCUIT
- Key in OFF position.
- PCM connector disconnected.
- Measure the resistance between:
( + ) FPDM Connector, Harness Side ( - ) PCM Connector, Harness Side FPM - Pin 1 FPM - Pin B46 - Observe the DMM for an indication of a concern while completing the following. The resistance changes suddenly when a concern is present.
- Wiggle, shake, and bend small sections of the wiring harness while working from the component to the module.
- Is a concern present?
Yes No ISOLATE the concern and REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.GO to KB15. - KB15 CHECK FOR AN INTERMITTENT SHORT TO VOLTAGE IN THE FPM CIRCUIT
- Key ON, engine OFF.
- Measure the voltage between:
( + ) FPDM Connector, Harness Side ( - ) Vehicle Battery FPM - Pin 1 Negative terminal - Observe the DMM for an indication of a concern while completing the following. The voltage changes suddenly when a concern is present.
- Wiggle, shake, and bend small sections of the wiring harness while working from the component to the module.
- Is a concern present?
Yes No ISOLATE the concern and REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.GO to KB16. - KB16 CHECK FOR AN INTERMITTENT SHORT TO GROUND IN THE FPM CIRCUIT
- Key in OFF position.
- Measure the resistance between:
( + ) FPDM Connector, Harness Side ( - ) FPM - Pin 1 Ground - Observe the DMM for an indication of a concern while completing the following. The resistance changes suddenly when a concern is present.
- Wiggle, shake, and bend small sections of the wiring harness while working from the component to the module.
- Is a concern present?
Yes No ISOLATE the concern and REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.Unable to duplicate or identify the concern at this time.
refer to PINPOINT TEST Z . - KB17 KOEO AND KOER DTC P1235: IS DTC P1235 PRESENT IN THE KOEO OR KOER SELF-TEST?
- Is DTC P1235 present in the KOEO or KOER self-test?
Yes No GO to KB18. CHECK for an intermittent concern,
GO to KB22. - KB18 CHECK THE FP CIRCUIT FOR AN OPEN IN THE HARNESS
- FPDM connector disconnected.
- PCM connector disconnected.
- Measure the resistance between:
( + ) PCM Connector, Harness Side ( - ) FPDM Connector, Harness Side FP - Pin B12 FP - Pin 6 - Is the resistance less than 5 ohms?
Yes No GO to KB19. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test. - KB19 CHECK THE FP CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS
- Key ON, engine OFF.
- Measure the voltage between:
( + ) FPDM Connector, Harness Side ( - ) FP - Pin 6 Ground - Is the voltage less than 1 V?
Yes No GO to KB20. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. - KB20 CHECK THE FP CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS
- Key in OFF position.
- Measure the resistance between:
( + ) FPDM Connector, Harness Side ( - ) FP - Pin 6 Ground - Is the resistance greater than 10K ohms?
Yes No GO to KB21. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. - KB21 CHECK THE FP CIRCUIT IN THE FPDM
- FPDM connector connected.
- Key ON, engine OFF.
- Measure the voltage between:
( + ) PCM Connector, Harness Side ( - ) FP - Pin B12 Ground - Is the voltage greater than 10.5 V?
Yes No GO to KB37. INSTALL a new FPDM. REFER to FUEL CHARGING AND CONTROLS - HYBRID .
CLEAR the DTCs. REPEAT the self-test. - KB22 CHECK FOR AN INTERMITTENT OPEN IN THE FP CIRCUIT
- Key in OFF position.
- FPDM connector disconnected.
- PCM connector disconnected.
- Measure the resistance between:
( + ) FPDM Connector, Harness Side ( - ) PCM Connector, Harness Side FP - Pin 6 FP - Pin B12 - Observe the DMM for an indication of a concern while completing the following. The resistance changes suddenly when a concern is present.
- Wiggle, shake, and bend small sections of the wiring harness while working from the component to the module.
- Is a concern present?
Yes No ISOLATE the concern and REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.GO to KB23. - KB23 CHECK FOR AN INTERMITTENT SHORT TO VOLTAGE IN THE FP CIRCUIT
- Key ON, engine OFF.
- Measure the voltage between:
( + ) FPDM Connector, Harness Side ( - ) Vehicle Battery FP - Pin 6 Negative terminal - Observe the DMM for an indication of a concern while completing the following. The voltage changes suddenly when a concern is present.
- Wiggle, shake, and bend small sections of the wiring harness while working from the component to the module.
- Is a concern present?
Yes No ISOLATE the concern and REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.GO to KB24. - KB24 CHECK FOR AN INTERMITTENT SHORT TO GROUND IN THE FP CIRCUIT
- Key in OFF position.
- Measure the resistance between:
( + ) FPDM Connector, Harness Side ( - ) FP - Pin 6 Ground - Observe the DMM for an indication of a concern while completing the following. The resistance changes suddenly when a concern is present.
- Wiggle, shake, and bend small sections of the wiring harness while working from the component to the module.
- Is a concern present?
Yes No ISOLATE the concern and REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.Unable to duplicate or identify the concern at this time.
refer to PINPOINT TEST Z . - KB25 DTC P1237: IS DTC P1237 PRESENT IN THE KOEO OR KOER SELF-TEST?
- Is DTC P1237 present in the KOEO or KOER self-test?
Yes No GO to KB26. CHECK for an intermittent concern,
GO to KB35. - KB26 DOES THE ENGINE START?
- Does the engine start?
Yes No GO to KB33. GO to KB27. - KB27 CHECK FPPWR, FPRTN, AND INTERNAL FUEL PUMP CIRCUIT RESISTANCE
- FPDM connector disconnected.
- Measure the resistance between:
( + ) FPDM Connector, Harness Side ( - ) FPDM Connector, Harness Side FPPWR - Pin 4 FPRTN - Pin 2 - Is the resistance less than 10 ohms?
Yes No GO to KB28. GO to KB31. - KB28 CHECK THE FPRTN CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS
- Key ON, engine OFF.
- Measure the voltage between:
( + ) FPDM Connector, Harness Side ( - ) FPRTN - Pin 2 Ground - Is the voltage less than 1 V?
Yes No GO to KB29. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. - KB29 CHECK THE FPPWR CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS
- Key in OFF position.
- Measure the resistance between:
( + ) FPDM Connector, Harness Side ( - ) FPPWR - Pin 4 Ground - Is the resistance greater than 10K ohms?
Yes No GO to KB30. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. - KB30 CHECK FOR VOLTAGE TO THE FP NOTE: During output test mode, the fuel pump stays commanded on for only about 5 seconds.
- FP connector disconnected.
- FPDM connector connected.
- Key ON, engine OFF.
- Enter output test mode. Refer toOUTPUT TEST MODE (OTM) .
- Command the outputs ON.
- Measure the voltage between:
( + ) FP Connector, Harness Side ( - ) FP Connector, Harness Side FPPWR FPRTN - Is the voltage greater than 10 V?
Yes No INSTALL a new FP. REFER to FUEL TANK AND LINES - HYBRID .
CLEAR the DTCs. REPEAT the self-test.VERIFY the vehicle battery was at a proper charge during the test.
VERIFY the pump ON command did not time out before the voltage check was made.
If OK, INSTALL a new FPDM. REFER to FUEL CHARGING AND CONTROLS - HYBRID .
CLEAR the DTCs. REPEAT the self-test. - KB31 ISOLATE THE OPEN IN THE FP CIRCUIT
- FP connector disconnected.
- Measure the resistance between:
( + ) FPDM Connector, Harness Side ( - ) FP Connector, Harness Side FPPWR - Pin 4 FPPWR FPRTN - Pin 2 FPRTN - Are the resistances less than 5 ohms?
Yes No GO to KB32. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test. - KB32 CHECK THE FUEL PUMP
- Measure the resistance between:
( + ) FP Connector, Harness Side ( - ) FP Connector, Harness Side FPPWR FPRTN - Is the resistance less than 10 ohms?
Yes No Unable to duplicate or identify the concern at this time.
VERIFY the results of the previous test steps.INSTALL a new FP. REFER to FUEL TANK AND LINES - HYBRID .
CLEAR the DTCs. REPEAT the self-test. - Measure the resistance between:
- KB33 CHECK THE FPPWR CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS
- FPDM connector disconnected.
- Key ON, engine OFF.
- Measure the voltage between:
( + ) FPDM Connector, Harness Side ( - ) FPPWR - Pin 4 Ground - Is the voltage less than 1 V?
Yes No GO to KB34. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. - KB34 CHECK THE FPRTN CIRCUIT(S) FOR A SHORT TO GROUND IN THE HARNESS
- Key in OFF position.
- Measure the resistance between:
( + ) FPDM Connector, Harness Side ( - ) FPRTN - Pin 2 Ground - Is the resistance greater than 10K ohms?
Yes No INSTALL a new FPDM. REFER to FUEL CHARGING AND CONTROLS - HYBRID .
CLEAR the DTCs. REPEAT the self-test.REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. - KB35 CHECK FOR AN INTERMITTENT OPEN OR SHORT IN THE FPPWR AND FPRTN CIRCUITS
- Key in OFF position.
- FPDM connector disconnected.
- Measure the resistance between:
( + ) FPDM Connector, Harness Side ( - ) FPDM Connector, Harness Side FPPWR - Pin 4 FPRTN - Pin 2 - Observe the DMM for an indication of a concern while completing the following. The resistance changes suddenly when a concern is present.
- Wiggle, shake, and bend small sections of the wiring harness while working from the component to the module.
- Is a concern present?
Yes No ISOLATE the concern and REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.GO to KB36. - KB36 CHECK FOR AN INTERMITTENT SHORT TO VOLTAGE IN THE FPRTN CIRCUIT
- Key ON, engine OFF.
- Measure the voltage between:
( + ) FPDM Connector, Harness Side ( - ) Vehicle Battery FPRTN - Pin 2 Negative terminal - Observe the DMM for an indication of a concern while completing the following. The voltage changes suddenly when a concern is present.
- Wiggle, shake, and bend small sections of the wiring harness while working from the component to the module.
- Is a concern present?
Yes No ISOLATE the concern and REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.Unable to duplicate or identify the concern at this time.
refer to PINPOINT TEST Z . - KB37 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
- Is the concern still present?
Yes No INSTALL a new PCM. REFER toFLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.