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Vehicle Speed Sensor ECM Code 24

  1. Check speedometer operation. If speedometer operates correctly, proceed to step 2). Repair or replace speedometer if speedometer is not operating properly.
  2. Disconnect 24-pin connector from ECM. Disconnect speedometer cable from speedometer head. On 4-speed models, disconnect 16-pin connector from ECU for the transaxle.
  3. On all applications, using ohmmeter, check resistance from White wire of ECM connector to ground. Measure resistance while rotating speedometer cable.
  4. If resistance varies between zero ohms and infinity, on M/T and 3-speed models, replace ECM. On 4-speed A/T models, go to step 9). On all applications, if reading was steady and less than one ohm, go to step 5). If reading was steady at infinite ohms, go to step 7).
  5. Disconnect 10-pin connector C2 from instrument cluster. Connect ohmmeter between White and Black/Pink wire terminals of instrument cluster. Measure resistance while rotating speedometer.
  6. If resistance varies between zero ohms and infinity, repair short to ground in White wire between instrument cluster and ECM on all models. On 4-speed A/T models, check for short to ground in White wire between instrument cluster and ECU. On all applications, if resistance did not fluctuate, replace vehicle speed sensor.
  7. Backprobe White wire of 10-pin connector C2 at instrument cluster. Measure resistance between White wire and ground while rotating speedometer. If resistance varies between zero ohms and infinity, repair open in White wire between instrument cluster and ECM on all models. If resistance did not fluctuate, proceed to step 8.
  8. Disconnect 10-pin connector C2 from instrument cluster. Measure resistance between Black/Pink wire and ground. If resistance is greater than .3 ohm, repair Black/Pink wire between instrument panel and battery. If reading is less than .3 ohm, replace vehicle speed sensor.
  9. Raise and support vehicle under lower control arms. Install 24-pin connector on ECM. DO NOT install 16-pin connector on ECU. With engine idling, retest ECM for stored trouble codes after all trouble codes are cleared. If Code 24 is not present, replace ECU. If Code 24 is set again, replace ECM.
NOTE: Following procedure applies to 4-speed A/T models with Code 24 stored in transaxle Electronic Control Unit (ECU) ONLY (not electronic control module) or when incorrect input from vehicle speed sensor is suspected.
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