Test Procedure
WARNING: This page is about a different variant/trim than selected.
- KT1 DTC P0A05: VERIFY THE CONCERN IS MECS PUMP 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, P1145, and P2279 present along with P0A05 indicate that actual concern is not MECS pump related.
Are the PCM DTCs P1A0C, P1A0D, P1145, and P2279 present during self-test?
Yes No DTC P0A05 was not set because of MECS pump related failure.
DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to DTC CHART .DTC P0A05 was set because of MECS pump related failure.
GO to KT2. - KT2 DTC P0A05: VERIFY 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 MECS PUMP RELAY CIRCUIT
- Key in OFF position.
- MECS Pump Relay connector disconnected.
- Connect a non-powered test lamp between:
(+) Vehicle Battery (-) MECS Pump Relay Connector, Harness Side Positive terminal MECSPR - Pin 1 - Key ON, engine OFF.
- Access the PCM and monitor 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 MECS PUMP RELAY
- Measure the voltage between:
(+) MECS Pump 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. - KT5 CHECK THE MECS PUMP RELAY RESISTANCE
- Key in OFF position.
- Measure the resistance between:
(+) MECS Pump Relay Connector, Component Side (-) MECS Pump Relay Connector, Component Side VPWR - Pin 2 MECSPR - 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 MECS Pump relay. CLEAR the DTCs. REPEAT the self-test. - KT6 CHECK THE MECS PUMP RELAY CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS
- PCM connector disconnected.
- Key ON, engine OFF.
- Measure the voltage between:
(+) PCM Connector, Harness Side (-) Vehicle Battery MECSPR - Pin T49 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 MECS PUMP RELAY CIRCUIT FOR AN OPEN CIRCUIT IN THE HARNESS
- Key in OFF position.
- Measure the resistance between:
(+) MECS Pump Relay Connector, Harness Side (-) PCM Connector, Harness Side MECSPR - Pin 1 MECSPR - Pin T49 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 MECS PUMP RELAY CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS
- Measure the resistance between:
(+) PCM Connector, Harness Side (-) Vehicle Battery MECSPR - Pin T49 Negative terminal Is the resistance greater than 10K ohms?
Yes No GO to KT10. REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test. - KT9 CHECK THE MECS PUMP RELAY CIRCUIT FOR AN INTERMITTENT CONCERN
- PCM connector connected.
- MECS Pump Relay connector connected.
- Key ON, engine OFF.
- Access the PCM and monitor the MECP PID.
- Command the MECP ON.
- Access the PCM and monitor the MECP_F PID.
Is a concern present during the wiggle test?
Yes No REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.GO 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 to FLASH 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.