2003 Acura 3.2TL BaseFACTORY OEM SERVICE PROCEDURE

Alternator Fr Signal: RSX

  1. Disconnect 4-pin harness connector from generator. Turn ignition switch on. Measure voltage by backprobing between Gray, 31-pin ECM/PCM harness connector terminal No. 24 (Brown/Yellow wire) and ECM/PCM 24-pin harness connector terminal No. 13 (White/Red wire). See Figure . See appropriate wiring diagram under ENGINE PERFORMANCE in WIRING DIAGRAMS. If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, go to step  4 .
  2. Turn ignition switch off. Reconnect generator 4-pin harness connector. Start engine and hold engine speed at 3,000 RPM with no load and transmission in park or neutral until radiator fan comes on. Let idle. Measure voltage between Gray, 31-pin ECM/PCM harness connector terminal No. 24 (Brown/Yellow wire) and PCM 24-pin harness connector terminal No. 13 (White/Red wire). If voltage decreases when headlights and rear defogger are turned on, ALT FR signal is okay. If voltage does not decrease when headlights and rear defogger are turned on, go to next step.
  3. Turn ignition switch off. Disconnect negative battery cable. Disconnect ECM/PCM 24-pin harness connector and generator 4-pin harness connector. Connect fused jumper wire between ground and generator 4-pin harness connector terminal No. 4 (White/Red wire). Using DVOM, check for continuity between ground and ECM/PCM 24-pin harness connector terminal No. 13 (White/Red wire). If continuity is present, check generator performance. See appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS. If continuity is not present, repair open in White/Red wire between PCM 24-pin harness connector terminal No. 13 and generator 4-pin harness connector terminal No. 4.
  4. Turn ignition switch off. Disconnect negative battery cable. Disconnect ECM/PCM 24-pin harness connector. Check continuity between ground and ECM/PCM 24-pin harness connector terminal No. 13 (White/Red wire). See Figure . See appropriate wiring diagram under ENGINE PERFORMANCE in WIRING DIAGRAMS. If continuity is present, repair short in White/Red wire between PCM 24-pin harness connector terminal No. 13 and generator 4-pin harness connector terminal No. 4. If continuity is not present, update PCM, if it does not have latest software or substitute known-good PCM, then recheck. If symptom or indication goes away, replace original PCM.
    NOTE: When substituting PCM, immobilizer code must be rewritten to replacement PCM using Honda PGM tester, or else engine will not start.
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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.

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