DTC P0645:00 [MZI-3.7 (PCM CONNECTOR (3 TYPES))]

id0102e4588000

DTC P0645:00

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 power supply between A/C relay terminal E and PCM terminal 1W
•  Short to ground in wiring between A/C relay terminal E and PCM terminal 1W
•  PCM connector or terminal malfunction
•  Open circuit in wiring between A/C relay terminal E and PCM terminal 1W
•  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 ignition key to ON (Engine running).
•  A/C switch and defroster switch off.
•  Access the ACCS PID using 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
•  PCM connector is disconnected.
•  Turn the ignition switch off.
•  Inspect continuity between A/C relay terminal E (wiring harness-side) and PCM terminal 1W (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 P0645:00 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.
•  Is the PENDING CODE for the DTC present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
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 (3 TYPES))].)
No
Troubleshooting completed.