CHARGING SYSTEM ON-VEHICLE INSPECTION

Note

If the battery is weak or if the engine is difficult to start, perform the following procedures.

CHECK BATTERY CONDITION

Check the battery for damage, deformation and leakage.

If damage, deformation or leakage is found, replace the battery.
Check the electrolyte quantity of each cell.

Tech Tips

Before checking the battery voltage, turn off all the electrical systems (headlights, blower motor, rear defogger, etc.).
- If the electrolyte quantity is below the lower line, replace the battery.
- If the electrolyte quantity is above the lower line, check the battery voltage when cranking the engine. If the voltage is below 9.6 V, recharge or replace the battery.

Check the voltage.

Turn the ignition switch off and turn on the headlights for 20 to 30 seconds. This will remove the surface charge from the battery.

Measure the voltage according to the value(s) in the table below.

Standard Voltage

Tester Connection	Condition	Specified Condition
Positive (+) terminal - Negative (-) terminal	20°C (68°F)	12.5 to 12.9 V

If the result is not as specified, charge the battery.

CHECK BATTERY TERMINAL AND FUSE
1. Check that the battery terminals are not loose or corroded.
  
  If the terminals are corroded, clean the terminals.
2. Measure the resistance of the charging fuses.
  
  Standard resistance
  
  Below 1 Ω
  
  Tech Tips
  
  For fuse locations, refer to Parts Location Click here.
  
  If the result is not as specified, replace the fuse.
CHECK V-RIBBED BELT
1. Check the belt for wear, cracks or other signs of damage.
  
  If any of the following defects is found, replace the fan and generator V belt.
  - The belt is cracked.
  - The belt is worn out to the extent that the cords are exposed.
  - The belt has chunks missing from the ribs.
2. Check that the belt fits properly in the ribbed grooves.
  
  Tech Tips
  
  Check with your hand to confirm that the belt has not slipped out of the grooves on the bottom of the pulley. If it has slipped out, replace the fan and generator V belt. Install a new fan and generator V belt correctly.
VISUALLY CHECK GENERATOR WIRING
1. Check that the wiring is in good condition.
  
  If the wiring is damaged, repair or replace the generator wire.
LISTEN FOR ABNORMAL NOISE FROM GENERATOR
1. Check that the generator does not emit any abnormal noise while the engine is running.
  
  If there is abnormal noise, replace the pulley or generator.
CHECK CHARGE WARNING LIGHT CIRCUIT
1. Turn the ignition switch to ON. Check that the charge warning light turns on.
2. Start the engine and check that the light turns off.
  
  If the light does not operate as specified, troubleshoot the charge warning light circuit.
CHECK CHARGING CIRCUIT WITHOUT LOAD
1. Check the charging circuit.
  1. Put the vehicle in a no-load test condition and run the engine at 2000 rpm. Using a voltmeter and ammeter, measure the battery voltage and current.
    
    Standard current
    
    10 A or less
    
    Standard voltage
    
    12.1 to 15.4 V
    
    If the result is not as specified, replace the generator.
    
    Tech Tips
    
    If the battery is not fully charged, the ammeter reading will sometimes be more than the standard current.
CHECK CHARGING CIRCUIT WITH LOAD
1. Put the vehicle in a load test condition (set the headlights to high beam and set the heater blower switch to Hi) and run the engine at 2000 rpm. Using an ammeter, measure the current.
2. Check the reading on the ammeter.
  
  Standard current
  
  30 A or higher
  
  If the ammeter reading is below the standard current, replace the generator.
  Tech Tips
  - If the ammeter reading is below the standard current even though the battery is fully charged, the load is not sufficient. Therefore, operate the wiper motor, rear window defogger, etc. to increase the load, and perform the measurement again.
  - If the battery is fully charged, the ammeter reading will sometimes be below the standard current.

Standard resistance
Below 1 Ω

Standard current
10 A or less

Standard voltage
12.1 to 15.4 V

Standard current
30 A or higher

CHECK CHARGING CONTROL SYSTEM

Inspect the wire harness.

w/ Entry and Start System:

Disconnect the H70 power management control ECU connector.
w/o Entry and Start System:

Disconnect the H73 power management control ECU connector.
Disconnect the C26 generator assembly connector.

Measure the resistance according to the value(s) in the table below.

Text in Illustration
*1	w/ Entry and Start System: Rear view of wire harness connector (to Power Management Control ECU)
*2	Front view of wire harness connector (to Generator Assembly)
*3	w/o Entry and Start System: Rear view of wire harness connector (to Power Management Control ECU)
*4	Front view of wire harness connector (to Generator Assembly)

Standard Resistance

w/ Entry and Start System:
Tester Connection	Condition	Specified Condition
H70-10 (RLO) - C26-1 (RLO)	Always	Below 1 Ω
H70-10 (RLO) - Body ground	Always	10 kΩ or higher
H70-10 (RLO) - Other terminal of H70 connector
C26-1 (RLO) - Body ground
C26-1 (RLO) - Other terminal of the generator connector

w/o Entry and Start System:
Tester Connection	Condition	Specified Condition
H73-14 (RLO) - C26-1 (RLO)	Always	Below 1 Ω
H73-14 (RLO) - Body ground	Always	10 kΩ or higher
H73-14 (RLO) - Other terminal of H73 connector
C26-1 (RLO) - Body ground
C26-1 (RLO) - Other terminal of the generator connector

Tech Tips

For the layout of the power management control ECU terminals, refer to Terminals of ECU Click here.

Inspect the power management control ECU.

Text in Illustration
*1	w/ Entry and Start System: Component with harness connected (Power Management Control ECU)
*2	w/o Entry and Start System: Component with harness connected (Power Management Control ECU)

Start the engine and warm it up for 20 to 30 minutes.
Connect an oscilloscope to the connector terminals of the power management control ECU.
Tech Tips
- Refer to the waveform table in the next step for terminal connections.
- For the layout of the power management control ECU terminals, refer to Terminals of ECU Click here.

Check that the power management control ECU output is a square wave as shown in the illustration when the vehicle is driven at a constant speed.

Waveform

Tester Connection		Tool Setting	Condition
w/ Entry and Start System	H70-10 (RLO) - H70-25 (E2)	2 V/DIV, 50 ms/DIV	Engine warmed up, charging control operating, vehicle driven at constant speed
w/o Entry and Start System	H73-14 (RLO) - H73-18 (E2)	2 V/DIV, 50 ms/DIV

Tech Tips

The oscilloscope waveform shown in the illustration is an example for reference only. Waveforms with noise or chattering are not shown.
As the duty cycle changes in accordance with the electrical load and battery condition, the output waveform also changes.

Check that the power management control ECU output is a square wave as shown in the illustration when the vehicle is accelerating.

Waveform

Tester Connection		Tool Setting	Condition
w/ Entry and Start System	H70-10 (RLO) - H70-25 (E2)	2 V/DIV, 50 ms/DIV	Engine warmed up, charging control operating, vehicle accelerating
w/o Entry and Start System	H73-14 (RLO) - H73-18 (E2)	2 V/DIV, 50 ms/DIV

Tech Tips

The oscilloscope waveform shown in the illustration is an example for reference only. Waveforms with noise or chattering are not shown.
As the duty cycle changes in accordance with the electrical load and battery condition, the output waveform also changes.

Check that the power management control ECU output is a square wave as shown in the illustration when the vehicle is decelerating.

Waveform

Tester Connection		Tool Setting	Condition
w/ Entry and Start System	H70-10 (RLO) - H70-25 (E2)	2 V/DIV, 50 ms/DIV	Engine warmed up, charging control operating, vehicle decelerating
w/o Entry and Start System	H73-14 (RLO) - H73-18 (E2)	2 V/DIV, 50 ms/DIV

Tech Tips

The oscilloscope waveform shown in the illustration is an example for reference only. Waveforms with noise or chattering are not shown.
As the duty cycle changes in accordance with the electrical load and battery condition, the output waveform also changes.