OPERATION
- The energized state of the alternator field coil is inputted from the alternator (terminal No. 4) to the engine-A/T-ECU (terminal No. 86).
FUNCTION
- A signal of the power supply duty ratio for the alternator field coil is inputted to the engine-A/T-ECU.
- In response to the signal, the engine-A/T-ECU detects the alternator output current and controls the idling speed according to the output current (electric load).
TROUBLE JUDGMENT
Check Condition
- Engine speed is 50 r/min or higher.
Judgment Criterion
- Input voltage from the alternator FR terminal has continued to be approximately battery positive voltage for 20 seconds.
PROBABLE CAUSE
- Failed alternator
- Open/short circuit in alternator FR terminal circuit or loose connector
- Failed engine-A/T-ECU
)
Q: Is the check result normal?
YES:
Go to Step 2 
.NO: Repair.
- Disconnect connector, and measure at male connector side.
- Ignition switch: ON
- Voltage between terminal No. 4 and earth.
OK: System voltage
Q: Is the check result normal?
YES:
Go to Step 6 .NO: Go to Step 3
.)
Q: Is the check result normal?
YES:
Go to Step 4 .NO: Repair.
- Check output line for open/short circuit.
Q: Is the check result normal?
YES:
Go to Step 5 .NO: Repair.
- Measure engine-A/T-ECU terminal voltage.
- Engine: Idle after warm-up
- Transmission: P range
- Radiator fan: Inactive
- Voltage between terminal No. 86 and earth.
OK: Switching the headlamps to ON from OFF causes the voltage to fall.
Q: Is the check result normal?
YES:
Go to Step 7 .NO: Go to Step 5
.
- Check output line for damage.
Q: Is the check result normal?
YES:
Go to Step 8 .NO: Repair.