2018 / ECLIPSE CROSS / EC - Workshop Manual
13 -FUEL > 13A-DIRECT INJECTION AND MULTIPOINT FUEL INJECTION (DI AND MPI) > TROUBLESHOOTING > DIAGNOSIS CODE PROCEDURES > CODE NO. P1603 BATTERY BACKUP CIRCUIT MALFUNCTION
Code No. P1603: Battery Backup Circuit Malfunction
OPERATION
- Power is directly supplied to the engine-ECU connector terminal BACK from the battery.
FUNCTION
- The engine-ECU checks open circuit in the battery backup line.
TROUBLE JUDGEMENT
Check Conditions
- Engine starting sequence was completed.
- Battery positive voltage is more than 10 V.
Judgement Criterion
- Battery backup voltage is less than 6 V for 2 seconds.
FAIL-SAFE AND BACKUP FUNCTION
- All diagnosis codes are set once failure judgement is completed.
PROBABLE CAUSES
- Open/short circuit or harness damage in battery backup line circuit or loose connector contact
- Failed engine-ECU
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-IIISE diagnosis code
- Temporarily place the ignition switch in LOCK (OFF) position, and 10 seconds after that, place it in ON position again.
Is the diagnosis code of P1603 set?
Go to Step 2.
Check end.
STEP 2. Perform voltage measurement at engine-ECU connector.
- Disconnect connector, and measure at harness side.
- Voltage between terminal BACK and body earth.
OK: System voltage
Is the check result normal?
Go to Step 3. Repair the connector(s), or check and repair of open circuit, and short circuit in BACK line between battery and engine-ECU connector.
STEP 3. Check of damage in BACK line between the battery and engine-ECU connector.
Is the check result normal?
Go to Step 4. Repair the connector(s) or wiring harness.
STEP 4. M.U.T.-IIISE diagnosis code
).