Diagnostic trouble code P1602 4GR-FSE Engine

DTC P1602 Deterioration of Battery

The ECM determines the battery power according to the voltage of the BATT terminal while the engine is running (not cranking).

DTC No.	DTC Detection Condition	Trouble Area
P1602	Battery power is 0 %	Battery ECM back-up power source circuit

1.INSPECT BATTERY

INSPECT BATTERY SPECIFIC GRAVITY
1. Check the specific gravity of each cell.
  Standard:
  
  1.25 to 1.29 at 20°C (68°F)
INSPECT BATTERY VOLTAGE
1. After the vehicle is driven for 20 minutes, stop the engine.
2. Turn the engine switch on (IG), and turn on the headlights, blower fan and defogger for 1 minute.
3. Turn the engine switch off.
4. Measure the battery voltage.
  Standard:
  
  12.5 to 12.9 V at 20°C (68°F)

NG

REPLACE BATTERY

OK

CHECK ECU POWER SOURCE CIRCUIT