Test Procedures

H1 DTCS P0053, P0054, P0132, P0133, P0135, P0138, P0141, P0171, P0172, P0201, P0202, P0203, P0204, P1127, P2195, P2196, P2270 AND P2271: CHECK FOR SELF-TEST DTCS

Are any of the following DTCs present during PCM or TCM self-test: P0053, P0054, P0132, P0133, P0135, P0138, P0141, P0171, P0172, P0201, P0202, P0203, P0204, P1127, P2195, P2196, P2270, or P2271?

Yes	No
For DTCs P0053 and P0054, GO to H10. For KOER DTCs P0132 and P0138, GO to H50. For continuous memory DTCs P0132 and P0138, GO to H55. For continuous memory DTC P0133, GO to H2. For DTCs P0135 and P0141, GO to H8. For continuous memory DTCs P0171 and P0172, GO to H15. For DTCs P0201, P0202, P0203 and P0204, GO to H32. For KOER DTC P1127, GO to H54. For DTCs P2195 and P2196, GO to H15. For DTCs P2270 and P2271, GO to H45.	Unable to duplicate or identify the fault at this time. Concern is elsewhere. RETURN to SYMPTOM CHARTS - HYBRID ESCAPE for further direction.

Yes

For DTCs P0053 and P0054, GO to H10.
For KOER DTCs P0132 and P0138, GO to H50.
For continuous memory DTCs P0132 and P0138, GO to H55.
For continuous memory DTC P0133, GO to H2.
For DTCs P0135 and P0141, GO to H8.
For continuous memory DTCs P0171 and P0172, GO to H15.
For DTCs P0201, P0202, P0203 and P0204, GO to H32.
For KOER DTC P1127, GO to H54.
For DTCs P2195 and P2196, GO to H15.
For DTCs P2270 and P2271, GO to H45.

Unable to duplicate or identify the fault at this time.
Concern is elsewhere. RETURN to SYMPTOM CHARTS - HYBRID ESCAPE for further direction.

H2 CONTINUOUS MEMORY DTC P0133: HO2S RESPONSE TEST

Key in ON position.
Access the diagnostic monitoring test results for the HO2S11.

Is the indicated value greater than the minimum threshold?

Yes	No
Key in OFF position. CLEAR the DTCs. CARRY OUT the HO2S monitor drive cycle. REFER to ON BOARD DIAGNOSTIC (OBD) DRIVE CYCLE .	GO to H3.

H3 CHECK FOR UNMETERED AIR LEAKS

NOTE: Fuel calculations can be affected by unmetered air leaks.

Carefully inspect the following areas for potential air leaks:
- Hoses connecting to the mass air flow MAF sensor assembly.
- Hoses connecting to the throttle body.
- Intake manifold gasket leaks.
- PCV disconnected.
- The vacuum lines are disconnected.
- Improperly seated engine oil dipstick, tube or oil fill cap.
- Exhaust leaks at flanges and gaskets.

Are any air leaks present?

Yes	No
REPAIR the source of the air leak.	GO to H4.

H4 CHECK HO2S CIRCUIT CONTINUITY

NOTE: HO2S is displayed as O2S on the diagnostic tool.

HO2S connector disconnected.
Check the connector (both halves) for any water contamination.

Connect a 5 amp fused jumper wire between the following:

Point A HO2S Connector, Harness Side	Point B HO2S Connector, Harness Side
HO2S Signal - Pin 3	VPWR - Pin 2

Key in ON position.
Access the PCM and monitor the HO2S Signal PID.

Is the voltage greater than 1 V?

Yes	No
Key in OFF position. INSTALL a new HO2S. CHANGE the engine oil and oil filter. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .	Key in OFF position. GO to H5

H5 CHECK THE HO2S CIRCUIT(S) FOR AN OPEN IN THE HARNESS

NOTE: A vehicle hoist may be required to access the HO2S harness. Refer to JACKING & LIFTING - ESCAPE & MARINER for the locations of the lifting points.

Remove the jumper wire(s).
Visually inspect the HO2S harness for exposed wiring, water contamination, corrosion, and proper assembly.
PCM connector disconnected.

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) HO2S Connector, Harness Side
HO2S Signal	HO2S Signal - Pin 3
SIGRTN - Pin E41	SIGRTN - Pin 4

Are the resistances less than 5 ohms?

Yes	No
GO to H6.	REPAIR the open circuit.

H6 CHECK THE HO2S CIRCUIT FOR A SHORT TO VPWR IN THE HARNESS

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) PCM Connector, Harness Side
HO2S Signal	VPWR - Pin B35, B36

Is the resistance greater than 10K ohms?

Yes	No
GO to H7.	For DTCs P0141 and P0161, GO to H8. For all others, INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .

H7 CHECK FOR A SOURCE OF POTENTIAL HO2S CONTAMINATION

Diagnose the following items as potential sources of HO2S contamination:
- Use of unapproved silicon sealers.
- Fuel contaminated by silicon additives.
- Excessive oil burning. (rings, valve seals, oil overfill).
- Glycol leaking internally in the engine.
- Lead-contaminated fuel.
- Short drive cycles in cold weather.
- Use of unapproved cleaning agents.

Were any of the above conditions or concerns found during inspection?

Yes	No
REPAIR the source of the contamination. CHANGE the engine oil and oil filter. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .	For DTCs P0141 or P0161, GO to H8. For all others, INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .

H8 DTCS P0135 AND P0141: VISUALLY INSPECT THE HO2S HARNESS

PCM connector connected.
Visually inspect the HO2S harness for exposed wiring, water contamination, corrosion, and correct assembly.

Are any exposed wiring, contamination, corrosion, or correct assembly concerns present?

Yes	No
REPAIR as necessary.	GO to H9.

H9 CARRY OUT THE KOEO ON DEMAND SELF-TEST

Key in ON position.

Are any of the following DTCs present: P0135, or P0141 .

Yes	No
Key in OFF position. GO to H10.	Key in OFF position. GO to H11.

H10 DTCS P0053 AND P0054: CHECK FOR VPWR IN THE HARNESS

NOTE: If DTCs P0135, or P0141 are present, all heater circuits require testing. DTCs are to be tested individually.

HO2S connector disconnected.
Key in ON position.

Measure the voltage between:

(+) HO2S Connector, Harness Side	(-) HO2S Connector, Harness Side
VPWR-Pin2	SIGRTN - Pin 4

Is the voltage greater than 10.5 V?

Yes	No
Key in OFF position. GO to H11.	REPAIR the open circuit.

H11 CHECK THE HO2S HEATER FOR SHORTS IN THE HARNESS

NOTE: If DTCs P0053, or P0054 are present, individually test the relevant circuits.

PCM connector disconnected.

Measure the resistance between:

( + ) HO2S Connector, Harness Side	(-) Vehicle Battery
HO2S Heater - Pin 1	Negative terminal

Measure the resistance between:

( + ) HO2S Connector, Harness Side	(-) HO2S Connector, Harness Side
HO2S Heater - Pin 1	SIGRTN - Pin 4
HO2S Heater - Pin 1	HO2S Case
HO2S Heater - Pin 1	VPWR - Pin 2
HO2S Heater - Pin 1	HO2S Signal - Pin 3

Are the resistances greater than 10K ohms?

Yes	No
GO to H12.	REPAIR the short circuit.

H12 CHECK THE HO2S CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) HO2S Connector, Harness Side
HO2S Heater	HO2S Heater - Pin 1

Is the resistance less than 5 ohms?

Yes	No
GO to H13.	REPAIR the open circuit.

H13 CHECK THE INTERNAL RESISTANCE OF THE HO2SHTR

Measure the resistance between:

( + ) HO2S Connector, Component Side	( - ) HO2S Connector, Component Side
HO2S Heater - Pin 1	VPWR - Pin 2

Is the resistance between 3 ohms - 30 ohms?

Yes	No
GO to H14.	INSTALL a new HO2S. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .

H14 CHECK THE HO2S HEATER CIRCUIT FOR A SHORT TO SIGRTN AND THE HO2S CASE

Measure the resistance between:

( + ) HO2S Connector, Component Side	(-) HO2S Connector, Component Side
HO2S Heater - Pin 1	SIGRTN - Pin 4
HO2S Heater - Pin 1	HO2S Case

Are the resistances greater than 10K ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM)	INSTALL a new HO2S.

H15 DTCS P0171, P0172, P2195 AND P2196: HO2S PERFORMANCE

NOTE: Address all continuous memory ignition and misfire DTCs before any KOER HO2S DTCs.

Check the intake air system for leaks, obstructions, and damage.
- Check the air filter element and housing for blockage.
- Verify the integrity of the PCV system.
- Check for vacuum leaks.

Are any concerns present during the visual inspection?

Yes	No
REPAIR as necessary.	GO to DC24

H16 CARRY OUT THE KOER ON DEMAND SELF-TEST

Disconnect the fuel vapor hose from the intake manifold and plug the fitting at the intake manifold.
Start the engine using the engine running diagnostic mode. Refer to DIAGNOSTIC MODES
Run the engine at 2,000 RPM for 5 minutes and return to idle.
Carry out the KOER self-test.

Is DTCP2195 present?

Yes	No
Key in OFF position. GO to H19.	Key in OFF position. For DTC P2196, GO to H25. For all others, GO to H17.

H17 DTCS P0171 OR P0172: CHECK FOR DTCS

Are DTCs P0171 or P0172 present?

Yes	No
GO to H27.	GO to H18.

H18 DETERMINE THE DTC BEING DIAGNOSED

Is the DTC recurring?

Yes	No
GO to H19.	CONNECT the fuel vapor line. Unable to identify the fault at this time. GO to Pinpoint Test Z .

H19 HO2S CIRCUIT TEST (WITH LEAN DTCS)

Disconnect the HO2S related to the current DTC.

Connect a 5 amp fused jumper wire between the following:

Point A HO2S Connector, Harness Side	Point B HO2S Connector, Harness Side
HO2S Signal - Pin 3	VPWR - Pin 2

Key on engine running.
Access the PCM and monitor the HO2S Signal PID.

Is the voltage greater than 1.3 V?

Yes	No
GO to H20.	GO to H22.

H20 CHECK THE SIGRTN CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the resistance between:

( + ) HO2S Connector, Harness Side	(-) Vehicle Battery
SIGRTN-Pin 4	Negative terminal

Is the resistance less than 5 ohms?

Yes	No
INSTALL a new HO2S. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .	GO to H21.

H21 CHECK THE SIGRTN CIRCUIT FOR AN OPEN IN THE HARNESS

PCM connector disconnected.

Measure the resistance between:

( + ) HO2S Connector, Harness Side	(-) PCM Connector, Harness Side
SIGRTN-Pin 4	SIGRTN-Pin B41, E41

Is the resistance less than 5 ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .	REPAIR the open circuit.

H22 CHECK THE HO2S CIRCUIT(S) FOR AN OPEN IN THE HARNESS

PCM connector disconnected.

Measure the resistance between:

( + ) HO2S Connector, Harness Side	(-) PCM Connector, Harness Side
HO2S Signal - Pin 3	HO2S Signal

Is the resistance less than 5 ohms?

Yes	No
GO to H23.	REPAIR the open circuit.

H23 CHECK THE HO2S CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) PCM Connector, Harness Side
HO2S Signal	SIGRTN-PinB41, E41

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) Vehicle Battery
HO2S Signal	Negative terminal

Is the resistance greater than 10K ohms?

Yes	No
GO to H24.	REPAIR the short circuit.

H24 CHECK THE HO2S CIRCUIT FOR A SHORT TO GROUND

HO2S connector connected.

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) PCM Connector, Harness Side
HO2S Signal	SIGRTN-Pin B41, E41

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) Vehicle Battery
HO2S Signal	Negative terminal

Is the resistance greater than 10K ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .	INSTALL a new HO2S. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .

H25 HO2S CIRCUIT TEST (WITH RICH DTCS)

HO2S connector disconnected.
Key in ON position.
Access the PCM and monitor the HO2S Signal PID.

Is the voltage less than 0.2 V?

Yes	No
Key in OFF position. INSTALL a new HO2S. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .	Key in OFF position. GO to H26.

H26 CHECK THE HO2S CIRCUIT FOR A SHORT TO THE VPWR OR HEATER CIRCUIT

PCM connector disconnected.

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) PCM Connector, Harness Side
HO2S Signal	HO2S Heater
HO2S Signal	VPWR - Pin B35, B36

Are the resistances greater than 10K ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .	REPAIR the short circuit.

H27 CHECK THE FUEL PRESSURE

WARNING: WHEN CHECKING THE FUEL SYSTEM REMEMBER THAT THE FUEL SYSTEM MAY STILL BE PRESSURIZED WHEN THE ENGINE IS SWITCHED OFF. ALWAYS FOLLOW THE INSTRUCTIONS RELATED TO FUEL SYSTEM PRESSURE RELIEF. ALL FUEL HANDLING SAFETY PRECAUTIONS MUST BE OBSERVED.

NOTE: During output state control, the fuel pump stays commanded on for only about 5 seconds.

Connect the battery charger to the vehicle.
Connect a mechanical fuel pressure gauge.
Key in ON position.
Access the PCM and control the FP PID.
Control the FP ON.

Is the pressure between 138-517 kPa (20.0 - 75.0 psi)?

Yes	No
Key in OFF position. EXIT the output state control. GO to H28.	EXIT the output state control. GO to Pinpoint Test HC .

H28 CHECK THE FUEL SYSTEM FOR PRESSURE STABILITY - FAST LEAKDOWN

Key in ON position.
Cycle the key several times to charge the fuel system.

Does the fuel pressure remain within 34 kPa (5 psi) of the highest reading after 10 seconds?

Yes	No
GO to H30.	GO to H29.

H29 CHECK FOR AN EXTERNAL FUEL LEAK

Is an external fuel leak present?

Yes	No
GO to Pinpoint Test HC .	GO to H32.

H30 CHECK THE FUEL SYSTEM FOR PRESSURE STABILITY - SLOW LEAKDOWN

Key in ON position.
Cycle the key several times to charge the fuel system.

Does the fuel pressure remain within 34 kPa (5 psi) of the highest reading after 1 minute?

Yes	No
GO to H31.	GO to HC7

H31 DETERMINE THE DTC BEING DIAGNOSED

Are any misfire DTCs displayed with the HO2S DTCs?

Yes	No
GO to H34.	GO to H37.

H32 CHECK THE INJECTOR FAULT PIDS AND ASSOCIATED DTCS

NOTE: If misfire DTCs are present, access only the injector fault PIDs corresponding to the misfire DTCs.

Access the PCM and monitor the INJ1F, INJ2F, INJ3F and INJ4F PIDs.

Is DTC P0201, P0202, P0203, or P0204 or an associated injector fault present?

Yes	No
GO to H34.	GO to H33.

H33 DETERMINE THE DTC BEING DIAGNOSED

Are any misfire DTCs present?

Yes	No
Go to HD14	GO to H37.

H34 CHECK THE FUEL INJECTOR(S) AND HARNESS RESISTANCES

NOTE: Continuous memory DTCs are erased during this test.

PCM connector disconnected.

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) PCM Connector, Harness Side
VPWR - Pin B35, B36	INJ1 - Pin E3
VPWR - Pin B35, B36	INJ2- PinE14
VPWR - Pin B35, B36	INJ3 - Pin E26
VPWR - Pin B35, B36	INJ4 - Pin E37

Are the resistances between 11 ohms -18 ohms?

Yes	No
For DTCs P0201, P0202, P0203 or P0204, GO to Pinpoint Test Z . For all others, INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .	GO to H35.

H35 CHECK THE FUEL INJECTOR HARNESS RESISTANCE

NOTE: Disconnect the suspect fuel injector harness connector. Only the suspect injector needs to be diagnosed.

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) Fuel Injector Connector, Harness Side
INJ1 - Pin E3	INJ - Pin 1
VPWR - Pin B35, B36	VPWR - Pin 2

Are the resistances less than 5 ohms?

Yes	No
GO to H36.	REPAIR the open circuit.

H36 CHECK FOR SHORTS BETWEEN CIRCUITS IN THE FUEL INJECTOR HARNESS

PCM connector disconnected.
Suspect fuel injector disconnected.

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) PCM Connector, Harness Side
VPWR - Pin B35, B36	INJ1 - Pin E3
VPWR - Pin B35, B36	INJ2-PinE14
VPWR - Pin B35, B36	INJ3 - Pin E26
VPWR - Pin B35, B36	INJ4 - Pin E37
PWRGND - Pin B47, B48, B49, B50	INJ1 - Pin E3
PWRGND - Pin B47, B48, B49, B50	INJ2-PinE14
PWRGND - Pin B47, B48, B49, B50	INJ3 - Pin E26
PWRGND - Pin B47, B48, B49, B50	INJ4 - Pin E37

Are the resistances greater than 10K ohms?

Yes	No
GO to H37.	REPAIR the short circuit.

H37 CARRY OUT THE FLOW TEST

Flow test the injector using the Fuel Injector Tester/Cleaner.

Is the flow rate for each injector within specification?

Yes	No
For DTCs P0171 or P2195, GO to H38. For DTC P0172, GO to Pinpoint Test Z . For DTC P2196, GO to H41.	INSTALL a new fuel injector. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .

H38 INSPECT THE INDUCTION SYSTEM FOR LEAKS

Carefully inspect the following areas for potential air leaks:
- Inlet tube(s) from the air cleaner to the throttle body.
- Gaskets sealing the upper to lower intake manifold.
- Vacuum hoses and lines for cracks, breaks, and proper connections.

Are any of these conditions present?

Yes	No
REPAIR as necessary.	For DTC P0171, GO to Pinpoint Test Z . For all others, GO to H39.

H39 CYLINDER COMPRESSION CHECK

NOTE: Use the misfire DTCs displayed or prior retrieval to determine which cylinder's compression to check.

Carry out cylinder compression checks. Refer to COMPRESSION TEST - HYBRID .

Is the suspect cylinder's compression within specification?

Yes	No
For DTC P2195, GO to H40. For DTC P2196, GO to H41. For all others, GO to HD22	REPAIR as necessary.

H40 CHECK THE HO2S OUTPUT VOLTAGE

NOTE: Fuel calculations can be affected by unmetered air leaks. DTC P2195 may result.

Check for the following:
- Water contamination in the connector.
- Leaking vacuum actuators.
- Engine sealing.
- EGR system.
- Positive crankcase ventilation (PCV) system.
- Unmetered air leaks between the throttle body and mass air flow (MAF) sensor assembly.
Visually inspect the HO2S circuit for exposed wiring, contamination, corrosion and correct assembly. Repair as necessary.
HO2S connector disconnected.
Start the engine using the engine running diagnostic mode. Refer to DIAGNOSTIC MODES .
Monitor the HO2S voltage while running the engine at 2,000 RPM for 3 minutes.

Measure the voltage between:

( + ) HO2S Connector, Component Side	(-) HO2S Connector, Component Side
HO2S Signal - Pin 3	SIGRTN - Pin 4

Is the voltage greater than 0.4 V?

Yes	No
Key in OFF position. GO to H43.	Key in OFF position. INSTALL a new HO2S. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .

H41 ATTEMPT TO GENERATE DTC P2195

HO2S connector disconnected.

Connect a 5 amp fused jumper wire between the following:

Point A HO2S Connector, Harness Side	Point B Vehicle Battery
HO2S Signal - Pin 3	Negative terminal

Carry out the KOER self-test.

Is DTC P2195 present?

Yes	No
Key in OFF position. GO to H42.	Key in OFF position. INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .

H42 HO2S VOLTAGE CHECK

Remove the jumper wire(s).
HO2S connector disconnected.
Disconnect the vacuum line from the vacuum tree.
Start the engine using the engine running diagnostic mode. Refer to DIAGNOSTIC MODES
Monitor the HO2S voltage while running the engine at 2,000 RPM for 30 seconds.

Measure the voltage between:

( + ) HO2S Connector, Component Side	(-) HO2S Connector, Component Side
HO2S Signal - Pin 3	SIGRTN - Pin 4

Is the voltage less than 0.4 V?

Yes	No
Key in OFF position. CONNECT all the hoses. GO to H43.	Key in OFF position. INSTALL a new HO2S. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .

H43 CARRY OUT A THOROUGH WIGGLE TEST ON THE HO2S HARNESS

HO2S connector connected.
Key on engine running.
Engine at normal operating temperature.
Access the PCM and monitor the HO2S Signal PID.
Wiggle, shake, and bend small sections of the wiring harness while working from the sensor to the PCM.

While monitoring the HO2S PID, did the HO2S stop switching?

Yes	No
Key in OFF position. REPAIR the open circuit.	Key in OFF position. GO to H44.

H44 TEST DRIVE THE VEHICLE WHILE MONITORING THE HO2S PID FOR SWITCHING

CAUTION: This test requires an observer to monitor the HO2S PID.

Access the PCM and monitor the HO2S Signal and LOOP PIDs.
Start the engine and let it idle until the vehicle goes into closed loop fuel control.
While an observer monitors the PIDs, test drive the vehicle in a manner consistent with the freeze frame data in an attempt to simulate the original fault.

Does the HO2S PID switch?

Yes	No
Key in OFF position. Unable to duplicate or identify the fault at this time. Completed testing did not find any faults.	Key in OFF position. INSTALL a new HO2S. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .

H45 DTC P2270, P2271: HO2S LACK OF SWITCHES TEST

NOTE: Address all continuous memory ignition and misfire DTCs before any KOER HO2S DTCs.

Visually inspect for:
- Pinched, shorted, and corroded wiring and pins.
- Oil or water contamination.
- Crossed sensor wires.
- Contaminated or damaged sensor.

Are any of the above conditions or concerns present?

Yes	No
REPAIR as necessary.	GO to H46.

H46 KOER DTC P2270, P2271: CHECK FOR DTCS

Key in ON position.
Start the engine using the engine running diagnostic mode. Refer to DIAGNOSTIC MODES .
Run the engine at 2,000 RPM for 5 minutes and return to idle.
Carry out the KOER self-test.

Are DTCs P2270 or P2271 present?

Yes	No
Key in OFF position. GO to H47.	Unable to duplicate or identify the fault at this time. GO to Pinpoint Test Z .

H47 CHECK FOR LEAKS IN THE EXHAUST SYSTEM

NOTE: Any exhaust leaks between the engine and the output of the catalyst can cause DTCs P2270 and P2271.

With the vehicle in NEUTRAL, position it on a hoist. Refer to JACKING & LIFTING - ESCAPE & MARINER for the locations of the lifting points.
Visually inspect for:
- Exhaust leaks at flanges and gaskets.
- HO2S not tightened to specification.
- Physical exhaust system concerns.
- Aftermarket exhaust.
- Punctures or cracks in the catalyst.

Are any exhaust system leaks present?

Yes	No
REPAIR as necessary.	GO to H48.

H48 CHECK THE HO2S CIRCUIT FOR A SHORT CIRCUIT IN THE HARNESS

PCM connector disconnected.
HO2S connector disconnected.

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) Vehicle Battery
HO2S Signal	Negative terminal

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) PCM Connector, Harness Side
HO2S Signal	SIGRTN-PinB41, E41
HO2S Signal	VPWR - Pin B35, B36
HO2S Signal	HO2S Heater

Are the resistances greater than 10K ohms?

Yes	No
GO to H49.	REPAIR the short circuit.

H49 CHECK THE VREF, HO2S SIGNAL, AND HO2S SIGRTN CIRCUITS FOR AN OPEN IN THE HARNESS

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) HO2S Connector, Harness Side
VPWR - Pin B35, B36	VPWR - Pin 2
HO2S Signal	HO2S Signal - Pin 3
SIGRTN-Pin B41, E41	SIGRTN - Pin 4

Are the resistances less than 5 ohms?

Yes	No
GO to H50.	REPAIR the open circuit.

H50 KOER DTCS P0132 AND P0138: CHECK THE HO2S CIRCUIT VOLTAGE

NOTE: Only diagnose the HO2S indicated by the DTC.

PCM connector connected.
HO2S connector connected.
Key in ON position.
Access the PCM and monitor the HO2S Signal PID.

Is the voltage greater than 1.5 volts?

Yes	No
Key in OFF position. GO to H53.	Key in OFF position. GO to H51.

H51 CHECK THE HO2S GROUND CIRCUIT IN THE PCM

PCM connector disconnected.

Measure the resistance between:

( + ) PCM Connector, Component Side	(-) PCM Connector, Component Side
PWRGND- Pin B47, B48, B49, B50	SIGRTN-PinB41, E41

Is the resistance less than 5 ohms?

Yes	No
GO to H52.	INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .

H52 CHECK THE HO2S CIRCUIT VOLTAGE

PCM connector connected.
HO2S connector disconnected.

Connect a 5 amp fused jumper wire between the following:

Point A HO2S Connector, Harness Side	Point B HO2S Connector, Harness Side
HO2S Signal - Pin 3	VPWR - Pin 2

Key in ON position.
Access the PCM and monitor the HO2S Signal PID.

Is the voltage greater than 1.5 V?

Yes	No
INSTALL a new HO2S.	INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .

H53 CHECK FOR OVER VOLTAGE IN THE PCM

Key in ON position.
HO2S connector disconnected.

Measure the voltage between:

( + ) HO2S Connector, Harness Side	(-) Vehicle Battery
SIGRTN-Pin4	Negative terminal
HO2S Signal - Pin 3	Negative terminal

Are the voltages greater than 1.5 V?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .	INSTALL a new HO2S. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .

H54 KOER DTC P1127: EXHAUST TEMPERATURE OUT OF RANGE

NOTE: Address all other DTCs before proceeding.

Key on engine running.
Access the PCM and monitor the HTR11 PID.

Is the PID state ON?

Yes	No
CARRY OUT the KOER self-test.	RUN the engine until the PID indicates ON. CARRY OUT the KOER self-test.

H55 CONTINUOUS MEMORY DTCS P0132 AND P0138: CHECK THE HO2S CIRCUIT VOLTAGE

Visually inspect the HO2S harness.
Check the connector (both halves) for any water contamination.
A vehicle hoist may be required to access the HO2S harness. Refer to JACKING & LIFTING - ESCAPE & MARINER for the locations of the lifting points.
Make sure the connectors are fully seated.
Key on engine running.
Access the PCM and monitor the O2S11SV and O2S12SV PIDs.

Are the voltages greater than 1.5 V?

Yes	No
GO to H57.	GO to H56.

H56 CARRY OUT A THOROUGH WIGGLE TEST ON THE HO2S HARNESS

Carry out a thorough wiggle test on the HO2S harness.

Did the voltage change while carrying out the wiggle test?

Yes	No
REPAIR as necessary.	GO to Pinpoint Test Z .

H57 CHECK THE HO2S SIGNAL FOR A SHORT TO POWER INSIDE THE SENSOR

Key in OFF position.
HO2S connector disconnected.
Key in ON position.
Access the PCM and monitor the O2S11SV and O2S12SV PIDs.

Are the voltages greater than 0.4 V?

Yes	No
GO to H58.	INSTALL a new HO2S. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .

H58 CHECK THE HO2S CIRCUIT FOR A SHORT TO POWER IN THE HARNESS

Key in OFF position.
HO2S connector disconnected.
PCM connector disconnected.

Measure the resistance between:

( + ) PCM Connector, Harness Side	(-) PCM Connector, Harness Side
HO2S Signal	VPWR - Pin B35, B36
HO2S Signal	VREF - Pin B40, E40

Are the resistances greater than 10K ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM)	REPAIR the short circuit.