Charging Circuit Troubleshooting
Charging Circuit TroubleshootingIf 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 as listed:
- Battery
- Charging system indicator test
- Alternator and regulator circuit test
- Alternator control system test
Charging System Indicator Test
1. Turn the ignition switch ON (II).
Does the charging system indicator come on?
YES - Go to step 2.
NO - Go to step 3.
2. Start the engine.
Does the charging system indicator go off?
YES - Charging system indicator circuit is OK. Go to the Alternator and Regulator Circuit Test.
NO - Go to step 3.
3. Troubleshoot the multiplex integrated control system.
Is the multiplex integrated control system OK ?
YES - Go to step 4.
NO - Repair the multiplex integrated control system.
4. Run the gauge control module self-diagnostic function.
Does the charge indicator flash?
YES - Go to step 5.
NO - Replace the gauge control module.
5. Turn the ignition switch OFF.
6. Disconnect the alternator 4P connector.
7. Turn the ignition switch ON (II).
8. Measure the voltage between alternator 4P connector terminal No. 1 and body ground.
Is there battery voltage?
YES - Go to step 9.
NO - Check for a blown No. 18(15 A) fuse in the under-dash fuse/relay box. If the fuse is OK, repair open in the wire between the alternator and under-dash fuse/relay box.
9. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC). Turn the ignition switch ON (II), and jump the SCS line with the HDS, then turn the ignition switch OFF.
NOTE: This step must be done to protect the engine control module (ECM)/powertrain control module (PCM) from damage.
10. Disconnect ECM/PCM connector E (31P).
11. Check for continuity between ECM/PCM connector terminal E11 and alternator 4P connector terminal No. 3.
Is there continuity?
YES - Go to step 12.
NO - Repair an open in the wire between the alternator and the ECM/PCM.
12. Check for continuity between ECM/PCM connector terminal E11 and body ground.
Is there continuity?
YES - Repair a short in the wire between the alternator and the ECM/PCM.
NO - Go to the Alternator and Regulator Circuit Test.
Alternator and Regulator Circuit Test
1. Be sure the battery connections are good, and that the battery is sufficiently charged.
2. Connect a VAT-40 (or equivalent tester), and turn the selector switch to position 1 (starting).
3. Shift to Park or Neutral, and start the engine. Hold the engine at 3,000 rpm, with no load until the radiator fan comes on, then let it idle.
4. Raise the engine speed to 2,000 rpm, and hold it there.
Is the voltage over 15.1 V?
YES - Replace the alternator or rear housing assembly.
NO - Go to step 5.
5. Release the accelerator pedal, and let the engine idle.
6. Make sure all accessories are turned off. Turn the selector switch to position 2 (charging).
7. Remove the inductive pick-up, and zero the ammeter.
8. Place the inductive pick-up over the B terminal wire of the alternator so that the arrow points away from the alternator.
9. Raise the engine speed to 2,000 rpm, and hold it there.
Is the voltage less than 13.5 V?
YES - Go to Alternator Control System Test.
NO - Go to step 10.
10. Apply a load with the VAT-40 until the battery voltage drops to between 12 - 13.5 V.
Is the amperage 87.5 A or more?
YES - The charging system is OK.
NOTE: If the charge system indicator is still on, replace the alternator.
NO - Repair or replace the alternator.
Alternator Control System Test
1. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC), and check for DTC's. If a DTC is present, diagnose and repair the cause before continuing with this test.
2. Disconnect the alternator 4P connector from the alternator.
3. Start the engine, and turn the headlights ON to high beam.
4. Measure voltage between alternator 4P connector terminal No. 2 and the positive terminal of the battery.
Is there 1 V or less?
YES - Go to step 5.
NO - Go to step 8.
5. Jump the SCS line with the HDS, then turn the ignition switch OFF.
NOTE: This step must be done to protect the engine control module (ECM) powertrain control module (PCM) from damage,
6. Disconnect ECM/PCM connector E (31P).
7. Check for continuity between ECM/PCM connector terminal E24 and body ground.
Is there continuity?
YES - Repair short in the wire between the alternator and ECM/PCM.
NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
8. Jump the SCS line with the HDS, then turn the ignition switch OFF.
NOTE: This step must be done to protect the engine control module (ECM)/powertrain control module (PCM) from damage.
9. Disconnect ECM/PCM connector E (31P).
10. Check for continuity between ECM/PCM connector terminal E24 and alternator 4P connector terminal No. 2.
Is there continuity?
YES - Replace or repair the alternator.
NO - Repair an open in the wire between the alternator and ECM/PCM.