Home ReviewsRefund
Home/Honda/Prelude/Honda Prelude V (1996-2001)/Repair manual/Testing & Diagnostics/DTC P0123 - THROTTLE POSITION (TP) SENSOR HIGH VOLTAGE INPUT
Contents Wiring diagrams Section: Testing & Diagnostics All sections

DTC P0123 - THROTTLE POSITION (TP) SENSOR HIGH VOLTAGE INPUT Honda Prelude V

Testing & Diagnostics 1 illustration ~468 words
  1. Start engine and run at 3000 RPM with no loads and transmission in Park or Neutral until radiator fan comes on. Turn ignition off. Turn ignition on. Using OBD-II scan tool, check TP sensor. If reading is about 10 percent with throttle fully closed and 90 percent with throttle fully opened, problem is intermittent. System is okay at this time. Check for poor connections or loose wires at TP sensor connector and PCM connector. See «WIRING DIAGRAMS»(ref-16355) article. If reading is not as specified, go to next step.
  2. Turn ignition off. Disconnect TP sensor 3-pin connector. Turn ignition on. Measure voltage between TP sensor harness 3-pin connector terminals No. 1 (Green/Black wire) and No. 3 (Yellow/Blue wire). see scheme 6 If about 5.0 volts does not exist, go to next step. If about 5.0 volts exists, replace throttle body (TP sensor is not serviced separately).
  3. Using backprobe set, measure voltage between PCM 16-pin connector "D" terminal D10 (Yellow/Blue wire) and terminal D11 (Green/Black wire). see scheme 4 If about 5.0 volts exists, repair open in Green/Black wire between PCM connector and TP sensor. See «WIRING DIAGRAMS»(ref-16355) article. If about 5.0 volts does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Scheme 27

Scheme 27: DTC P0131 - PRIMARY HO2S-1 SENSOR LOW VOLTAGE
Scheme 27: DTC P0131 - PRIMARY HO2S-1 SENSOR LOW VOLTAGE
  1. Perform PCM reset procedure. See «TESTS W/CODES - INTRODUCTION»(ref-16345) article. Start engine and run at 3000 RPM with no loads and transmission in Park or Neutral until radiator fan comes on. Road test vehicle with transmission in "2" position (A/T) or 4th gear (M/T). Using OBD-II scan tool, check HO2S-1 output voltage during acceleration using Wide Open Throttle (WOT). If voltage stays at 0.1 volt or less, go to next step. If voltage does not stay at 0.1 volt or less, problem is intermittent. System is okay at this time. Check for poor connections or loose wires between HO2S-1 connector and PCM connectors. See «WIRING DIAGRAMS»(ref-16355) article.
  2. Check fuel pressure. See FUEL SYSTEM in «BASIC TESTING»(ref-16344) article. If fuel pressure is within specification, go to next step. If fuel pressure is not within specification, repair fuel supply system as necessary.
  3. Turn ignition off. Disconnect HO2S-1, 4-pin connector. Start engine and run at idle. Using OBD-II scan tool, check HO2S-1 output voltage. If voltage stays at 0.1 volt or less, go to next step. If output voltage does not stay at 0.1 volt or less, replace primary HO2S-1.
  4. Turn ignition off. Disconnect PCM 16-pin connector "D". Check for continuity between ground and HO2S-1, 4-pin harness connector terminal No. 2 (White wire). (Scheme 27) If continuity exists, repair short in White wire between PCM 16-pin connector D7 and HO2S-1. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

More articles — Engine Controls - Tests W/codes - Tests