Civic (D16Y5 Engine With M/T) & Prelude
- Turn ignition off. Disconnect generator 4-pin connector (3-pin on Canadian Civic models). Turn ignition on. Using backprobe set, measure voltage between PCM 32-pin connector "A" terminal No. 9 (Brown/Black wire) and 31-pin connector "C" terminal No. 17 (White/Red wire on Civic or White/Green wire on Prelude). See PIN VOLTAGE CHARTS
article. 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 31-pin connector "C". Check for continuity between ground and PCM 31-pin harness connector "C" terminal No. 17 (White/Red wire on Civic or White/Green wire on Prelude). If continuity exists, repair short in White/Red wire (Civic) or White/Green wire (Prelude) between PCM 31-pin connector "C" and generator connector. If continuity does not exist, substitute a known-good PCM and recheck. See SUBSTITUTING PCM in SELF-DIAGNOSTICS - INTRODUCTION
article. If symptom or indication goes away, replace original PCM.
- Turn ignition off and reconnect generator 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. Using backprobe set, measure voltage between PCM 32-pin connector "A" terminals No. 9 (Brown/Black wire) and 31-pin connector "C" terminal No. 17 (White/Red wire on Civic or White/Green wire on Prelude). Turn headlights and rear defogger on. If voltage does not decrease when headlights and rear defogger are turned on, go to next step. If voltage decreases when headlights and rear defogger are turned on, generator FR signal is okay.
- Turn ignition off and disconnect negative battery cable. Disconnect PCM 31-pin connector "C". Disconnect generator 4-pin (3-pin on Canadian Civic models) connector. Connect a fused jumper wire between ground and generator harness connector terminal No. 4 (White/Red wire) on US models or No. 1 (White/Red wire) on Canadian models. See Fig 1. Check for continuity between ground and PCM 31-pin harness connector "C" terminal No. 17 (White/Red wire on Civic or White/Green wire on Prelude). If continuity exists, problem is within generator or regulator. See appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS. If continuity does not exist, repair open in White/Red wire on Civic or White/Green wire on Prelude between PCM 31-pin connector "C" and generator.
Courtesy of AMERICAN HONDA MOTOR CO., INC.