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Continuously Variable Transmission (CVT)

WARNING: This page is about a different car, the 2000 Honda Civic. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING DTCS in SELF-DIAGNOSTICS - INTRODUCTION article. Connect SCS service connector. Start engine and run at 3000 RPM with no loads and transmission in Park or Neutral until radiator fan comes on. Drive vehicle for about 10 minutes. Maintain engine speed at 1700-2500 RPM. If DTC P1491 is indicated, go to next step. If DTC P1491 is not indicated, problem is intermittent. System is okay at this time. Check for poor connections or loose wires at EGR valve and PCM connectors. See appropriate wiring diagram in WIRING DIAGRAMS article.
  2. Turn ignition off. Disconnect vacuum hose from top of EGR valve. See VACUUM DIAGRAMS article. Connect vacuum pump/gauge to hose. Start engine and allow it to idle. If vacuum does not exist, go to next step. If vacuum exists, disconnect EGR solenoid valve 2-pin connector. Recheck EGR vacuum hose for vacuum. If vacuum exists, check EGR system hose routing. If hose routing is okay, replace EGR control solenoid valve. If vacuum does not exist, substitute a known good PCM, then recheck. If symptom or indication goes away, replace original PCM.
  3. Connect vacuum pump/gauge to EGR valve. With engine at idle, apply 8 in. Hg vacuum to EGR valve. If engine stalls or runs rough, and EGR valve holds vacuum, go to next step. If engine does not stall or run rough, or EGR valve does not hold vacuum, replace EGR valve.
  4. Turn ignition off. Disconnect EGR valve lift sensor 3-pin connector. EGR valve lift sensor 3-pin connector is located at top of EGR, on right side of engine. Turn ignition on. Measure voltage between EGR valve lift sensor harness connector terminals No. 2 and No. 3. If 5 volts exist, go to step  6. If 5 volts does not exist, go to next step.
  5. Using backprobe set, measure voltage between PCM 31-pin connector "C" terminals No. 18 (Green/Black wire) and No. 28 (Yellow/Blue wire). See Figure. If 5 volts exist, check for open in Yellow/Blue wire between PCM 31-pin connector "C" and EGR valve. If 5 volts does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
  6. Turn ignition off. Measure resistance between EGR valve lift sensor terminals No. 1 and No. 2. See Figure. If resistance is 100,000 ohms or higher, replace EGR valve. If resistance is not 100,000 or higher, go to next step.
  7. Measure resistance between EGR valve lift sensor terminals No. 1 and No. 3. See Figure. If resistance is 100,000 ohms or higher, go to next step. If resistance is not 100,000 or higher, replace EGR valve.
  8. Reconnect EGR valve lift sensor connector. Turn ignition on. Using backprobe set, measure voltage between PCM 31-pin connector "C" terminals No. 6 (White/Black wire) and No. 18 (Green/Black wire). If 1.2 volts exists, go to step  10. If 1.2 volts does not exist, go to next step.
  9. Using backprobe set, check for continuity between ground and PCM 31-pin connector "C" terminal No. 6 (White/Black wire). If continuity does not exist, check for open in White/Black wire between EGR valve and PCM 31-pin connector "C". If continuity exists, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
  10. Ensure vacuum pump/gauge is connected to vacuum hose from top of EGR valve. Disconnect EGR valve lift connector. Start engine and allow it to idle. Using fused jumper wire, connect battery voltage to EGR control solenoid valve terminal No. 1 (Black/Yellow wire). See appropriate wiring diagram in WIRING DIAGRAMS article. Using a second fused jumper wire, ground EGR control solenoid valve terminal No. 2 (Red wire). Observe vacuum gauge. If there is about 8.0 in. Hg vacuum within one second, go to step  12. If there is not about 8.0 in. Hg vacuum within one second, go to next step.
  11. Turn ignition off. Check vacuum hoses between EGR control solenoid valve, EGR valve and intake manifold for leaks, restrictions or misrouting. See VACUUM DIAGRAMS article. Repair or replace hoses as necessary. If hoses are okay, replace EGR control solenoid valve.
  12. Turn ignition off. Disconnect PCM 25-pin connector "B". See Figure. Check for continuity in Red wire between PCM 25-pin connector "B" terminal No. 6 and EGR control solenoid valve harness connector terminal No. 2. If continuity exists, go to next step. If continuity does not exist, check for open in Red wire between PCM 25-pin connector "B" and EGR valve connector. See appropriate wiring diagram in WIRING DIAGRAMS article.
  13. Turn ignition off and remove jumper wires. Disconnect EGR solenoid valve 2-pin connector. Disconnect PCM 32-pin connector "A". Check for continuity in Red wire between PCM 32-pin connector terminal No. 7 and EGR solenoid valve harness connector terminal No. 2. If continuity exists, go to next step. If continuity does not exist, check for open in Red wire between PCM 32-pin connector "A" and EGR valve connector. See appropriate wiring diagram in WIRING DIAGRAMS article.
  14. Check for continuity between ground and EGR valve harness connector terminal No. 2 (Red wire). See appropriate wiring diagram in WIRING DIAGRAMS article. If continuity does not exist, go to next step. If continuity exists, check for short in Red wire between PCM 25-pin connector "B" and EGR valve connector. See appropriate wiring diagram in WIRING DIAGRAMS article.
  15. Check for continuity between ground and EGR control solenoid valve harness connector terminal No. 1 (Black wire). If continuity does not exist, check for open in Black wire between EGR control solenoid valve and ground connection located at right front of engine, below air cleaner box. See appropriate wiring diagram in WIRING DIAGRAMS article. If continuity exists, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
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