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Home >> Honda >> 1999 >> Prelude Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Idle Control System >> Generator Fr Signal >> Civic & Prelude
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Civic & Prelude

  1. Turn ignition off. Disconnect generator 4-pin connector (3-pin on Canadian 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/Green wire). If about 5 volts exists, go to step  3. If about 5 volts does not exist, go to next step.
  2. 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/Green wire). If continuity exists, repair short in circuit between PCM 31-pin connector "C" and generator connector. If continuity does not exist, substitute a known-good PCM and recheck. On Prelude, see SUBSTITUTING PCM in SELF-DIAGNOSTICS - INTRODUCTION article. If symptom or indication goes away, replace original PCM.
  3. 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/Green wire). 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, generator FR signal is okay.
  4. Turn ignition off. Disconnect negative battery cable. Disconnect PCM 31-pin connector "C". Disconnect generator 4-pin (3-pin on Canadian 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. Using backprobe set, check for continuity between ground and PCM 31-pin connector "C" terminal No. 17 (White/Green wire). 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/Green wire between PCM 31-pin connector "C" and generator.
Fig 1: Identifying Generator Connector (US Models Connector Is Shown; Canadian Is Similar)
G96I10502Courtesy of AMERICAN HONDA MOTOR CO., INC.
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