DTC U2109:00 [PCM (e-SKYACTIV)]

id300202041700

Outline

System malfunction location	Backup power supply system: Circuit malfunction
Detection condition	•  The PCM detects a malfunction in the backup power supply shut-off circuit and backup power supply output circuit.
Fail-safe	•  Refer to "DTC Table" and "Fail-safe Function Malfunction Contents Table". (See DTC TABLE [PCM (e-SKYACTIV)].)
Possible cause	•  DTCs are stored in the body control module (BCM) •  Lead-acid battery malfunction •  Short to ground in backup power supply shut off circuit •  Short to power supply in backup power supply shut off circuit •  Open circuit in backup power supply shut off circuit •  Short to ground in backup power supply output circuit •  Short to power supply in backup power supply output circuit •  Open circuit in backup power supply output circuit •  DC-DC converter malfunction •  Backup power supply malfunction (Backup power supply voltage is lower or higher than specified value) •  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	VERIFY BODY CONTROL MODULE (BCM) DTCs •  Perform the DTC inspection for the body control module (BCM) . (See DTC INSPECTION.) •  Are any DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [BODY CONTROL MODULE (BCM) (E)].)
		No	Go to the next step.
3	INSPECT 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	Perform the symptom troubleshooting "DISCHARGED LEAD-ACID BATTERY". (See DISCHARGED LEAD-ACID BATTERY.)
4	INSPECT BACKUP POWER SUPPLY 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.
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 BACKUP POWER SUPPLY SHUT OFF 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 BACKUP POWER SUPPLY SHUT OFF CIRCUIT FOR SHORT TO POWER SUPPLY •  Inspect the applicable circuit for a short to power supply. (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 BACKUP POWER SUPPLY SHUT OFF CIRCUIT FOR OPEN CIRCUIT •  Inspect the applicable circuit for an 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 BACKUP POWER SUPPLY OUTPUT 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.
10	INSPECT BACKUP POWER SUPPLY OUTPUT CIRCUIT FOR SHORT TO POWER SUPPLY •  Inspect the applicable circuit for a short to power supply. (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.
11	INSPECT BACKUP POWER SUPPLY OUTPUT CIRCUIT FOR OPEN CIRCUIT •  Inspect the applicable circuit for an 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.
12	INSPECT BACKUP POWER SUPPLY FOR MALFUNCTION •  Inspect the applicable part. (See BACKUP POWER SUPPLY 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 BACKUP POWER SUPPLY REMOVAL/INSTALLATION [(E)].)
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.