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DTC P0646:00 [PCM (SKYACTIV-D)]

id0102t5587900

Outline

System malfunction location

A/C relay circuit low input

Detection condition

•  When all of the following conditions are met, a condition whereby the A/C relay control circuit voltage is less than the specification continues for 5 s.

―  Battery positive voltage: 8—16 V

―  0.5 s have elapsed after ignition is switched ON (engine off or on)

―  During A/C relay off control

Fail-safe

•  PCM restricts engine-transaxle integration control. (ATX)

•  Inhibits the A/C control.

Possible cause

•  A/C relay malfunction

•  IG1 relay No.2 malfunction

•  F47 15 A fuse malfunction

•  Short to ground in A/C relay control circuit

•  Short to ground in A/C relay power supply circuit

•  PCM connector or terminals malfunction

•  PCM malfunction

System malfunction location	A/C relay circuit low input
Detection condition	• When all of the following conditions are met, a condition whereby the A/C relay control circuit voltage is less than the specification continues for 5 s. ― Battery positive voltage: 8—16 V ― 0.5 s have elapsed after ignition is switched ON (engine off or on) ― During A/C relay off control
Fail-safe	• PCM restricts engine-transaxle integration control. (ATX) • Inhibits the A/C control.
Possible cause	• A/C relay malfunction • IG1 relay No.2 malfunction • F47 15 A fuse malfunction • Short to ground in A/C relay control circuit • Short to ground in A/C relay power supply circuit • PCM connector or terminals malfunction • PCM malfunction

Diagnostic Procedure

Step

Inspection

Results

Action

1

RECORD VEHICLE STATUS WHEN DTC WAS DETECTED TO UTILIZE WITH REPEATABILITY VERIFICATION

•  Record the freeze frame data/snapshot data.

Note

•  Recording can be facilitated using the screen capture function of the PC.

—

Go to the next step.

2

VERIFY RELATED REPAIR INFORMATION OR SERVICE INFORMATION AVAILABILITY

•  Verify related Service Bulletins, on-line repair information, or Service Information availability.

•  Is any related Information available?

Yes

Perform repair or diagnosis according to the available information.

•  If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3

INSPECT A/C RELAY

•  Switch the ignition off.

•  Remove the A/C relay.
(See RELAY LOCATION [(E)].)

•  Inspect the A/C relay.
(See RELAY INSPECTION.)

•  Is there any malfunction?

Yes

Repair or replace the malfunctioning location and perform the repair completion verification.

(See RELAY LOCATION [(E)].)

No

Go to the next step.

4

INSPECT IG1 RELAY No.2

•  Remove the IG1 relay No.2.
(See RELAY LOCATION [(E)].)

•  Inspect the IG1 relay No.2.
(See RELAY INSPECTION.)

•  Is there any malfunction?

Yes

Repair or replace the malfunctioning location and perform the repair completion verification.

(See RELAY LOCATION [(E)].)

No

Go to the next step.

5

INSPECT F47 15 A FUSE

•  Remove the F47 15 A Fuse.

•  Inspect the F47 15 A Fuse.

•  Is the fuse normal?

Yes

Reinstall the F47 15 A Fuse, then go to the next step.

No

Replace the F47 15 A Fuse and perform the repair completion verification.

6

INSPECT A/C RELAY CONTROL CIRCUIT FOR SHORT TO GROUND

•  Inspect the applicable circuit for a short to ground.
(See CIRCUIT INSPECTION.)

•  Is the circuit normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

7

INSPECT A/C RELAY POWER SUPPLY CIRCUIT FOR SHORT TO GROUND

•  Inspect the applicable circuit for a short to ground.
(See CIRCUIT INSPECTION.)

•  Is the circuit normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

8

INSPECT PCM CONNECTOR FOR MALFUNCTION

•  Inspect the applicable connector and terminal.
(See CONNECTOR INSPECTION.)

•  Are the connector and terminal normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

Repair completion verification 1

VERIFY THAT VEHICLE IS REPAIRED

•  Install/connect the part removed/disconnected during the troubleshooting procedure.

•  Clear the DTC recorded in the memory.
(See CLEARING DTC.)

•  Replicate the vehicle conditions at the time the DTC was detected using the following procedure.

―  Start the engine.

―  Turn the air conditioner on and off.

•  Perform the DTC inspection for the PCM.
(See DTC INSPECTION.)

•  Is the same Pending DTC present?

Yes

Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.

(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)

If the CAN communication is normal, perform the diagnosis from Step 1.

•  If the malfunction recurs, replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [SKYACTIV-D 1.8].)

No

Go to the next step.

Repair completion verification 2

VERIFY IF OTHER DTCs DISPLAYED

•  Perform the DTC inspection.
(See DTC INSPECTION.)

•  Are any other DTCs displayed?

Yes

Repair the malfunctioning location according to the applicable DTC troubleshooting.

No

DTC troubleshooting completed.

Step	Inspection	Results	Action
1	RECORD VEHICLE STATUS WHEN DTC WAS DETECTED TO UTILIZE WITH REPEATABILITY VERIFICATION • Record the freeze frame data/snapshot data. Note • Recording can be facilitated using the screen capture function of the PC.	—	Go to the next step.
2	VERIFY RELATED REPAIR INFORMATION OR SERVICE INFORMATION AVAILABILITY • Verify related Service Bulletins, on-line repair information, or Service Information availability. • Is any related Information available?	Yes	Perform repair or diagnosis according to the available information. • If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT A/C RELAY • Switch the ignition off. • Remove the A/C relay. (See RELAY LOCATION [(E)].) • Inspect the A/C relay. (See RELAY INSPECTION.) • Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification. (See RELAY LOCATION [(E)].)
3		No	Go to the next step.
4	INSPECT IG1 RELAY No.2 • Remove the IG1 relay No.2. (See RELAY LOCATION [(E)].) • Inspect the IG1 relay No.2. (See RELAY INSPECTION.) • Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification. (See RELAY LOCATION [(E)].)
4		No	Go to the next step.
5	INSPECT F47 15 A FUSE • Remove the F47 15 A Fuse. • Inspect the F47 15 A Fuse. • Is the fuse normal?	Yes	Reinstall the F47 15 A Fuse, then go to the next step.
5		No	Replace the F47 15 A Fuse and perform the repair completion verification.
6	INSPECT A/C RELAY CONTROL CIRCUIT FOR SHORT TO GROUND • Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Go to the next step.
6		No	Repair or replace the malfunctioning location and perform the repair completion verification.
7	INSPECT A/C RELAY POWER SUPPLY CIRCUIT FOR SHORT TO GROUND • Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning location and perform the repair completion verification.
8	INSPECT PCM CONNECTOR FOR MALFUNCTION • Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) • Are the connector and terminal normal?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning location and perform the repair completion verification.
Repair completion verification 1	VERIFY THAT VEHICLE IS REPAIRED • Install/connect the part removed/disconnected during the troubleshooting procedure. • Clear the DTC recorded in the memory. (See CLEARING DTC.) • Replicate the vehicle conditions at the time the DTC was detected using the following procedure. ― Start the engine. ― Turn the air conditioner on and off. • Perform the DTC inspection for the PCM. (See DTC INSPECTION.) • Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. • If the malfunction recurs, replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [SKYACTIV-D 1.8].)
Repair completion verification 1		No	Go to the next step.
Repair completion verification 2	VERIFY IF OTHER DTCs DISPLAYED • Perform the DTC inspection. (See DTC INSPECTION.) • Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
Repair completion verification 2		No	DTC troubleshooting completed.