Charging Circuit Troubleshooting

If the charging system indicator does not come on or does not go off, or the battery is dead or low, test the following items in the order listed below:

Battery
Charging system indicator
Alternator/regulator circuit
Alternator control system

Charging System Indicator Test


1.Turn the ignition switch ON (II).

Does the charging system indicator come on?


YES - Go to 2.


NO - Go to 9.


2.Start the engine.

Does the charging system indicator go off?


YES - Charging system indicator circuit is OK.n


NO - Go to 3.


3.Turn the ignition switch OFF.

4.Disconnect the alternator 4P connector from the alternator.

5.Turn the ignition switch ON (II).

Does the charging system indicator come on?


YES -

  • Without navigation system: Turn the ignition switch OFF, and repair the short in the WHT/BLU wire. If the WHT/BLU wire is shorted to ground, the voltage regulator in the alternator may be damaged.n
  • With navigation system: Go to 6.

NO - Repair the alternator components.


6.Turn the ignition switch OFF.

7.Disconnect the 12P connector from the AVN unit.

8.Turn the ignition switch ON (II).

Does the charging system indicator come on?


YES - Turn the ignition switch OFF, and repair the short in the WHT/BLU wire. If the WHT/BLU wire is shorted to ground, the voltage regulator in the alternator may be damaged.n


NO - Check that the terminals are firmly seated at the connectors. If OK, substitute a known-good AVN unit and recheck.n


9.Connect the alternator 4P connector terminal No. 3 to body ground with a jumper wire. Turn the ignition switch ON (II).

 

Does the charging system indicator come on?


YES - Go to 10.


NO - Turn the ignition switch OFF. Check for a blown No. 3 (7.5 A) fuse and a blown charging system indicator bulb. If the fuse and bulb are OK, repair the open in the YEL or BLK/YEL wire to the indicator bulb.n

10.Measure the voltage at the No. 1 terminal of the alternator 4P connector with the ignition switch ON (II).

 

Is there battery voltage?


YES - Go to alternator and regulator circuit test.


NO - Repair open in the YEL or BLK/YEL wire between the alternator and the under-dash fuse/relay box.n

Alternator and Regulator Circuit Test


1.Be sure the battery is sufficiently charged and in good condition.

2.Hook up the following equipment:

  • Ammeter, 0-400 A
  • Voltmeter, 0-20 V (accurate within 0.1 V)

 

3.Start the engine. Hold the engine at 3,000 rpm (min-1) with no load shift lever in Park or Neutral, until the radiator fan comes on then let it idle.

4.Raise the engine speed to 2,000 rpm (min-1) and hold it there.

5.Turn the headlights (high beam) on, and measure voltage at the alternator terminal.

Is the voltage between 13.9 and 15.1 V?


YES - Go to 6.


NO - Repair the alternator components.n


6.Read the voltage at 13.5 V.

NOTE: Adjust the voltage by turn the blower motor, rear window defogger, brake lights and etc. on.

Is the voltage 60 A or more?


YES - Alternator/regulator operation is OK.n


NO - Repair the alternator components.n

Alternator Control System Test


1.Check for proper operation of the Electrical Load Detecter (ELD) by checking that the Malfunction Indicator Lamp (MIL) is off and there is no Diagnostic Trouble Code (DTC) for ELD failure:


2.Disconnect the alternator 4P connector from the alternator.

3.Start the engine, and turn the headlights (high beam) ON.

4.Measure voltage between the alternator 4P connector terminal No. 2 and the positive terminal of the battery.

 

Is there 1 V or less?


YES - Go to 9.


NO - Go to 5.


5.Turn the headlight and ignition switch OFF.

6.Disconnect the negative cable from the battery.

7.Disconnect Engine Control Module (ECM)/Powertrain Control Module (PCM) connector B (24P).

8.Check for continuity between ECM/PCM connector terminal B18 and body ground.

 

Is there continuity?


YES - Repair short to ground in the wire between the alternator and  ECM/ PCM.n


NO - Check that the terminals are firmly seated at the connectors. If OK, substitute a known-good ECM/PCM, and recheck. If prescribed voltage is now available, replace the original  ECM/ PCM.n


9.Turn the headlight and ignition switch OFF.

10.Disconnect the negative cable from the battery.

11.Disconnect ECM/PCM connector B (24P).

12.Check for continuity between ECM/PCM connector terminal B18 and alternator 4P connector terminal No. 2.

 

Is there continuity?


YES - Repair the alternator.n


NO - Repair open in the wire between the alternator and  ECM/ PCM.n