Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Charging System Indicator Circuit Troubleshooting
- Turn the ignition switch ON (II).
Does the charging system indicator come on?
YES - Go to step 2.
NO - Go to step 14.
- Start the engine. Hold the engine speed at 2,000 rpm for 1 minute.
Does the charging system indicator go off?
YES - Charging system indicator circuit is OK. Go to ALTERNATOR AND REGULATOR CIRCUIT TROUBLESHOOTING ).
NO - Go to step 3.
- Do the gauge control module self-diagnostic function procedure (see SELF-DIAGNOSTIC FUNCTION
).
Does the charging system indicator flash?
YES - Go to step 4.
NO - Replace the gauge control module (see GAUGE CONTROL MODULE REPLACEMENT ).
- Turn the ignition switch to LOCK (0).
- Disconnect the alternator 4P connector.
- Turn the ignition switch to ON (II).NOTE: The charging system indicator may come on and then go off.
Does the charging system indicator go off?
YES - Replace the alternator (see ALTERNATOR REMOVAL AND INSTALLATION ), or repair the alternator (see ALTERNATOR OVERHAUL ).
NO - Go to step 7.
- Turn the ignition switch to LOCK (0).
- Connect the Honda Diagnostic System (HDS) to the data link connector (DLC) (see step 2 in HOW TO USE THE HDS (HONDA DIAGNOSTIC SYSTEM) ).
- Turn the ignition switch ON (II).
- Make sure the HDS communicates with the vehicle and the engine control module (ECM)/powertrain control module (PCM). If it doesn't communicate, troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
- Jump the SCS line with the HDS, then turn the ignition switch to LOCK (0).NOTE: This step must be done to protect the ECM/PCM from damage.
- Disconnect ECM/PCM connector B (24P).
- Check for continuity between ECM/PCM connector terminal B10 and body ground.
Is there continuity?
YES - Repair short in the wire between the alternator and the ECM/PCM.
NO - Update the ECM/PCM if it does not have the latest software (see UPDATING THE ECM/PCM ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).
- Do the gauge control module self-diagnostic function procedure (see SELF-DIAGNOSTIC FUNCTION
).
Does the charging system indicator flash?
YES - Go to step 15.
NO - Replace the gauge control module (see GAUGE CONTROL MODULE REPLACEMENT ).
- Turn the ignition switch to LOCK (0).
- Disconnect the alternator 4P connector.
- Connect alternator 4P connector terminal No. 3 and body ground with a jumper wire.
- Turn the ignition switch ON (II).
Does the charging system indicator come on?
YES - Replace the alternator (see ALTERNATOR REMOVAL AND INSTALLATION ), or repair the alternator (see ALTERNATOR OVERHAUL ).
NO - Disconnect the jumper wire, then go to step 19.
- Turn the ignition switch to LOCK (0).
- Connect the HDS to the DLC (see step 2 in HOW TO USE THE HDS (HONDA DIAGNOSTIC SYSTEM) ).
- Turn the ignition switch ON (II).
- Make sure the HDS communicates with the vehicle and the ECM/PCM. If it doesn't communicate, troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
- Jump the SCS line with the HDS, then turn the ignition switch OFF.NOTE: This step must be done to protect the ECM/PCM from damage.
- Disconnect ECM/PCM connector B (24P).
- Check for continuity between ECM/PCM connector terminal B10 and the alternator 4P connector terminal No. 3.
Is there continuity?
YES - Update the ECM/PCM if it does not have the latest software (see UPDATING THE ECM/PCM ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).
NO - Repair open in the wire between the alternator and the ECM/PCM.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.