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Speed Indicator Jumps Up And Down Erratically

  1. Remove speed sensor from transmission. Check that all gear are in good condition. Ensure retaining clip is installed and gear does not slip on shaft. If okay, go to next step. If not, replace drive gear and retaining clip.
  2. Disconnect wiring to speed sensor. Using ohmmeter, check resistance between 2 wires in harness going to speed sensor. Ohmmeter should read more than 500 ohms resistance. If reading is correct, go to next step. If not, repair wiring, cruise control, or instrument cluster for short circuits.
  3. Using ohmmeter, check speed sensor resistance. Ohmmeter should read 200-230 ohms resistance. If reading is correct, go to next step. If not, replace speed sensor. Recheck speedometer operation.
  4. Connect speed sensor wiring. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION in this article. Using an ohmmeter, check for intermittent resistance between pin "11C" and pin "7C" (ground). See INSTRUMENT CLUSTER PIN CONNECTOR IDENTIFICATION illustration. If okay, replace speedometer module. If not, repair connectors or wiring from cluster to speed sensor. After repairs, check speedometer operation.
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