Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P1602: Deterioration of Battery [12/2012 - ]: Procedure
- CHECK CHARGING SYSTEM
- Check the charging system.
Refer to ON-VEHICLE INSPECTION [12/2012 - 11/2013] , or refer to ON-VEHICLE INSPECTION [11/2013 - 10/2015] , or refer to ON-VEHICLE INSPECTION [10/2015 - ]
Result:
NG
REPAIR OR REPLACE CHARGING SYSTEM
Result:
OK
See step 2
- Check the charging system.
- CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)
- Disconnect the A58 generator control ECU assembly connector.
*a Front view of wire harness connector
(to Generator Control ECU Assembly) - Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A58-5 (AM21) - Body ground Always 11 to 14 V
Result:
OK
CHECK FOR INTERMITTENT PROBLEMS: HOW TO PROCEED WITH TROUBLESHOOTING [12/2012 - 11/2013] , HOW TO PROCEED WITH TROUBLESHOOTING [11/2013 - 10/2015] , HOW TO PROCEED WITH TROUBLESHOOTING [10/2015 - 08/2016] , HOW TO PROCEED WITH TROUBLESHOOTING [08/2016 - 08/2017] , HOW TO PROCEED WITH TROUBLESHOOTING [08/2017 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- Disconnect the A58 generator control ECU assembly connector.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
