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.
- KT1 DTC P0A05: VERIFY THE CONCERN IS MECP RELATED NOTE: The DTC P0A05 may be set as the result of the PCM taking a limited operating strategy (LOS) action.
The PCM DTCs P1A0C, P1A0D, and P2105, or P1145 and P2279 present along with P0A05 indicate that actual concern is not MECP related.
- Are the PCM DTCs P1A0C, P1A0D, and P2105, or P1145 and P2279 present during self-test?
Yes No DTC P0A05 was not set because of MECP related failure.
DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO toDIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .DTC P0A05 was set because of MECP related failure.
GO to KT2. - KT2 DTC P0A05: VERIFY THAT THE CONCERN IS PRESENT
- Is DTC P0A05 present in the KOEO or KOER self-test?
Yes No GO to KT3. GO to KT9. - KT3 CHECK THE FUNCTIONALITY OF THE MECP CIRCUIT AT THE RELAY
- Key in OFF position.
- MECP Relay connector disconnected.
- Connect a non-powered test lamp between:
( + ) Vehicle Battery ( - ) MECP Relay Connector, Harness Side Positive terminal MECPR - Pin 1 - Key ON, engine OFF.
- Access the PCM and control the MECP PID.
- Cycle the MECP PID on and off.
- Does the test lamp turn on and off when output state control is commanded on and off?
Yes No GO to KT4. GO to KT6. - KT4 CHECK THE VPWR VOLTAGE TO THE MECP RELAY
- Measure the voltage between:
( + ) MECP Relay Connector, Harness Side ( - ) Vehicle Battery VPWR - Pin 2 Negative terminal - Is the voltage greater than 10.5 V?
Yes No GO to KT5. REPAIR the circuit. CHECK the condition of related fuses/fuse links. If damaged, CHECK the VPWR circuit for a short to ground.
CLEAR the DTCs. REPEAT the self-test. - Measure the voltage between:
- KT5 CHECK THE MECP RELAY RESISTANCE
- Key in OFF position.
- Measure the resistance between:
( + ) MECP Relay Connector, Component Side ( - ) MECP Relay Connector, Component Side VPWR - Pin 2 MECPR - Pin 1 - Is the resistance between 40 - 90 ohms?
Yes No Unable to duplicate or identify the concern at this time.
GO to KT9.INSTALL a new MECP relay. CLEAR the DTCs. REPEAT the self-test. - KT6 CHECK THE MECP CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS
- Key ON, engine OFF.
- Measure the voltage between:
( + ) PCM Connector, Harness Side ( - ) Vehicle Battery MECPR - Pin T4 Negative terminal - Is the voltage less than 1 V?
Yes No GO to KT7. REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test. - KT7 CHECK THE MECP CIRCUIT FOR AN OPEN IN THE HARNESS
- Key in OFF position.
- PCM connector disconnected.
- Measure the resistance between:
( + ) MECP Relay Connector, Harness Side ( - ) PCM Connector, Harness Side MECPR - Pin 1 MECPR - Pin T4 - Is the resistance less than 5 ohms?
Yes No GO to KT8. REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test. - KT8 CHECK THE MECP CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS
- Measure the resistance between:
( + ) PCM Connector, Harness Side ( - ) Vehicle Battery MECPR - Pin T4 Negative terminal - Is the resistance greater than 10K ohms?
Yes No GO to KT10. REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test. - Measure the resistance between:
- KT9 CHECK THE MECP CIRCUIT FOR AN INTERMITTENT CONCERN
- PCM connector connected.
- MECP Relay connector connected.
- Key ON, engine OFF.
- Access the PCM and control the MECP PID.
- Command the MECP ON.
- Access the PCM and monitor the MECP_F PID.
- Carefully wiggle all accessible wiring and connectors associated with the circuit and look for a change in the PID state.
- Is a concern present during the wiggle test?
Yes No REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.refer to PINPOINT TEST Z . - KT10 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.