DTC P0686:00 [PCM (e-SKYACTIV)]

id300202029300

Outline

System malfunction location	Main relay No.2 circuit low input
Detection condition	•  The PCM detects that the 12 V power supply voltage to terminal DG of the PCM is not supplied or the supply voltage is low even though main relay No.2 is controlled at on.
Fail-safe	•  Refer to "DTC Table" and "Fail-safe Function Malfunction Contents Table". (See DTC TABLE [PCM (e-SKYACTIV)].)
Possible cause	•  Lead-acid battery malfunction •  DC-DC converter malfunction •  Main relay No.2 malfunction •  PCM connector or terminals malfunction •  Short to ground or open circuit in main relay No.2 power supply circuit •  Short to ground in any of the following main relay No.2 circuits. ―  Power supply circuit ―  Control circuit •  Open circuit in any of the following main relay No.2 circuits. ―  Power supply circuit ―  Control circuit •  Short to ground or open circuit in PCM power supply circuit •  PCM malfunction

Diagnostic Procedure

Step	Inspection	Results	Action
1	RECORD VEHICLE STATUS WHEN DTC WAS DETECTED TO UTILIZE WITH REPEATABILITY VERIFICATION •  Record the snapshot data. Note •  Recording can be facilitated using the screen capture function of the PC.	—	Go to the next step.
2	NSPECT LEAD-ACID BATTERY FOR MALFUNCTION •  Inspect the applicable part. (See LEAD-ACID BATTERY INSPECTION) •  Is the part normal?	Yes	Go to the next step.
		No	Recharge or replace the lead-acid battery and perform the repair completion verification 1. (See LEAD-ACID BATTERY RECHARGING.) (See LEAD-ACID BATTERY REMOVAL/INSTALLATION.)
3	VERIFY DC-DC CONVERTER DTC •  Perform the DTC inspection for the DC-DC converter. (See DTC INSPECTION.) •  Are any DC-DC converter related DTCs displayed?	Yes	Go to the next step.
		No	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [DC-DC CONVERTER (e-SKYACTIV)])
4	INSPECT MAIN RELAY No.2 FOR MALFUNCTION •  Inspect the applicable part. (See RELAY INSPECTION.) •  Is the part normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification 1. (See RELAY LOCATION [(E)].)
5	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 1.
6	INSPECT MAIN RELAY No.2 POWER SUPPLY CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT •  Inspect the power supply circuit for an open circuit and 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 1.
8	INSPECT PCM 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 1.
7	INSPECT MAIN RELAY No.2 POWER SUPPLY CIRCUIT AND CONTROL CIRCUIT FOR OPEN CIRCUIT •  Inspect the applicable circuit for a open circuit. (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 1.
9	INSPECT PCM POWER SUPPLY CIRCUIT AND CONTROL CIRCUIT FOR OPEN CIRCUIT •  Inspect the applicable circuit for open circuit. (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 1.
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. Warning •  While performing this step, always operate the vehicle in a safe and lawful manner. •  When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. ―  Drive the vehicle under the snapshot data condition. •  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 [L.H.D. (E)].) (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [R.H.D.].) 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.)
		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.