Alternator (Alt) Fr Signal
NOTE:
This signal informs PCM when alternator is charging.
- Turn ignition off. Disconnect alternator 4-pin (3-pin on Canadian models) connector. Turn ignition on. Measure voltage between PCM connector terminal A9 and terminal C17. See Figure. If about 5 volts exists, go to step 3). If about 5 volts does not exist, go to next step.
- Turn ignition off and disconnect negative battery cable. Disconnect PCM connector "C". Check for continuity between ground and PCM connector terminal C17. If continuity exists, repair short in wire between PCM connector and alternator connector. If continuity does not exist, substitute known-good PCM and recheck for about 5 volts. If about 5 volts now exists, replace original PCM.
- Turn ignition off and reconnect alternator connector. Start engine and run at 3000 RPM with no loads and transmission in Park or Neutral, until radiator fan comes on. Allow engine to idle. Measure voltage between PCM connector terminal A9 and terminal C17. If voltage does not decrease when headlights and rear defogger is turned on, go to next step. If voltage decreases when headlights and rear defogger is turned on, alternator FR signal is okay.
- Turn ignition off. Disconnect negative battery cable. Disconnect PCM connector "C". See Figure. Disconnect alternator 4-pin (3-pin on Canadian models) connector. Connect a jumper wire between ground and alternator harness connector White/Red wire terminal. Check for continuity between ground and PCM connector terminal C17. If continuity exists, problem is within alternator or regulator. If continuity does not exist, repair open in wire between PCM connector and alternator harness connector.