DTC P0645 [MZI-3.7 (PCM CONNECTOR (2 TYPES))]

id0102e3833500

DTC P0645

A/C relay control circuit
DETECTION CONDITION
•  Monitors the A/C relay control circuit output from the PCM. The test fails when the PCM grounds the A/C relay control circuit, excessive current draw is detected on the A/C relay control circuit; or, with the A/C relay control circuit not grounded by the PCM, voltage is not detected on the A/C relay control circuit (the PCM expects to detect vehicle power voltage coming through the A/C relay coil to the A/C circuit).
POSSIBLE CAUSE
•  A/C relay connector or terminal malfunction
•  Open circuit in wiring between main relay terminal No.1 D and A/C relay terminal A
•  Short to ground in wiring between A/C relay terminal E and PCM terminal 1N
•  Short to power supply between A/C relay terminal E and PCM terminal 1N
•  PCM connector or terminal malfunction
•  Open circuit in wiring between A/C relay terminal E and PCM terminal 1N
•  A/C relay malfunction
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record FREEZE FRAME DATA on the repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
INSPECT THAT THE ACCS PID IS OFF
•  Turn the ignition switch to the ON position (Engine running).
•  A/C switch and defroster switch off.
•  Access the ACCS PID using the M-MDS.
•  Is the PID state off?
Yes
Go to the next step.
No
ACCS input to PCM is requesting A/C. Inspect A/C system operation, then go to Step 12.
(See DIAGNOSTIC TROUBLE CODE NUMBER INSPECTION.)
(See TROUBLESHOOTING INDEX.)
4
INSPECT A/C RELAY CONNECTOR FOR POOR CONNECTOR
•  Turn the ignition switch off.
•  Disconnect the A/C relay connector.
•  Inspect for poor connection (such as damaged, pulled-out pins, corrosion, etc.).
•  Are there any malfunction?
Yes
Repair or replace suspected part, then go to Step 12.
No
Go to the next step.
5
INSPECT A/C RELAY POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT
•  Turn the ignition switch to the ON position (Engine off).
•  Measure voltage between A/C relay terminal A (wiring harness-side) and body ground.
•  Is voltage B+?
Yes
Go to the next step.
No
Repair or replace suspected part, then go to Step 12.
6
INSPECT A/C RELAY CONTROL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Turn the ignition switch to the ON position (Engine off).
•  Remove the A/C relay.
•  Measure voltage between A/C relay terminal E (wiring harness-side) and body ground.
•  Is voltage B+?
Yes
Repair or replace suspected part, then go to Step 12.
No
Go to the next step.
7
INSPECT A/C RELAY CONTROL CIRCUIT FOR SHORT TO GROUND
•  Install the A/C relay.
•  Turn the ignition switch off.
•  Inspect continuity between A/C relay terminal E (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Repair or replace suspected part, then go to Step 12.
No
Go to the next step.
8
INSPECT PCM CONNECTOR FOR POOR CONNECTION
•  Turn ignition switch to off.
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged, pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace suspected part, then go to Step 12.
No
Go to the next step.
9
INSPECT A/C RELAY CONTROL CIRCUIT FOR OPEN CIRCUIT
•  Turn the ignition switch off.
•  Inspect continuity between A/C relay terminal E (wiring harness-side) and PCM terminal 1N (wiring harness-side).
•  Is there continuity?
Yes
Go to the next step.
No
Repair or replace suspected part, then go to Step 12.
10
INSPECT A/C RELAY
•  Inspect A/C relay.
•  Is A/C relay normal?
Yes
Go to the next step.
No
Replace the A/C relay. Start the engine. Turn on the A/C switch. Wait for 15 s. Turn off the A/C switch, then go to Step 12.
11
INSPECT FOR CORRECT PCM OPERATION
•  Disconnect all the PCM connectors.
•  Visually inspect for:
―  Pushed out pins
―  Corrosion
•  Connect all the PCM connectors and verify that they seat correctly.
•  Retrieve DTCs using the M-MDS.
•  Is the PENDING CODE for this DTC present?
Yes
Go to the next step.
No
The system is correctly. Go to the next step.
12
VERIFY TROUBLESHOOTING OF DTC P0645 HAS BEEN COMPLETED
•  Verify that all disconnected connectors reconnected.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform the “KOEO or KOER self-test” using the M-MDS.
•  Is the PENDING CODE for the DTC present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [MZI-3.7].)
No
Go to the next step.
13
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZI-3.7 (PCM CONNECTOR (2 TYPES))].)
No
Troubleshooting completed.