Alternator Fr Signal
- Connect PGM-FI test harness between ECU and ECU connectors. Disconnect connector "B" from main wire harness only; DO NOT
disconnect from ECU. Turn ignition on. Check voltage between terminals B14 (positive) and A18 (negative). See Fig 1
. If voltage is NOT about 5 volts, substitute a good know ECU, and recheck.
- If voltage is bout 5 volts, turn ignition off. Reconnect connector "B" to main harness. Start engine, and warm it to operating temperature. Check voltage between ECU terminals B14 (positive) and A18 (negative).
- If voltage decreases when headlights or rear defogger are turned on, alternator FR signal is okay. Turn ignition off. Remove alternator sensor fuse for 10 seconds to reset ECU. If voltage does not decrease, go to next step.
- Disconnect connector "B" from ECU only. Disconnect negative battery cable from battery. Check for continuity between PGM-FI test harness terminal B14 and ground. If continuity is present, disconnect Green connector from alternator.
- Check again for continuity between PGM-FI test harness terminal B14 and ground. If continuity is not present, check alternator for possible failure. If continuity is present, repair Red/White wire between alternator and terminal B14 on ECU.
Courtesy of AMERICAN HONDA MOTOR CO., INC.