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 listed below:
- 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 - Check the multiplex integrated control system as indicated by the DTC.
4. Perform the gauge control module self test procedure.
Does the charging system 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 (15A) 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 B (24P).
11. Check for continuity between ECM/PCM connector terminal B10 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 B10 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 the 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 60 A or more?
YES - The charging system is OK.
NOTE: If the charging system indicator is still on, replace the alternator or the rear housing assembly
NO - Replace or repair the alternator.
Alternator Control System Test
1. Check for proper operation of the electrical load detector (ELD) by checking the malfunction indicator lamp (MIL).
2. 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
3. Disconnect the alternator 4P connector from the alternator
4. Start the engine, and turn the headlights ON to high beam
5. 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 6
NO - Go to step 9
6. 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.
7. Disconnect engine control module ECM/PCM connector B (24P)
8. Check for continuity between ECM/PCM connector terminal B18 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.
9. 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) for damage
10. Disconnect ECM/PCM connector B (24P)
11. Check for continuity between ECM/PCM connector terminal B18 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.