Alternator FR Signal Circuit Troubleshooting (L12A/L13A CVT-KM/KP)
Alternator FR Signal Circuit Troubleshooting
| 1. | Disconnect the alternator 2P connector. |
| 2. | Turn the ignition switch ON (II). |
| 3. | Measure voltage between PCM connector terminals A24 and B13.
 PCM CONNECTORSWire side of female terminalsLG1 (BRN/YEL)ALTF(WHT/RED)A (31P)B (24P) Is there about 5 V? YES - Go to 4. NO - Go to 13. |
| 4. | Turn the ignition switch OFF. |
| 5. | Reconnect the alternator 2P connector. |
| 6. | Start the engine. Hold the engine at 3,000 rpm (min-1) with no load (in Park or neutral) until the radiator fan comes on, then let it idle. |
| 7. | Measure voltage between PCM connector terminals A24 and B13.
 PCM CONNECTORSWire side of female terminalsLG1 (BRN/YEL)ALTF(WHT/RED)A (31P)B (24P) Does the voltage decrease when the headlights and rear window defogger are turned on? YES - The alternator FR signal is OK.n NO - Go to 8. |
| 8. | Turn the ignition switch OFF. |
| 9. | Disconnect PCM connector B (24P). |
| 10. | Disconnect the alternator 2P connector. |
| 11. | Connect the alternator 2P connector terminal No. 2 and body ground with a jumper wire.
 ALTERNATOR 2P CONNECTORALTF (WHT/RED)JUMPER WIREWire side of female terminals |
| 12. | Check for continuity between body ground and PCM connector terminal B13.
 PCM CONNECTOR B (24P)Wire side of female terminalsALTF(WHT/RED) Is there continuity? YES - Test the alternator.n NO - Repair open in the wire between the PCM (B13) and the alternator.n |
| 13. | Turn the ignition switch OFF. |
| 14. | Disconnect PCM connector B (24P). |
| 15. | Check for continuity between body ground and PCM connector terminal B13.
 PCM CONNECTOR B (24P)Wire side of female terminalsALTF(WHT/RED) Is there continuity? YES - Repair short in the wire between the PCM (B13) and the alternator.n NO - Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM.n |