Speedometer & Odometer Do Not Operate Properly
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1.Unplug VSS buffer, located under passenger side end of instrument panel. Turn ignition on. Check for battery voltage between harness connector Brown wire and ground. If battery voltage exists, go to next step. If battery voltage does not exist, repair short or open in Pink/Black wire. 2.Check for battery voltage between Brown wire and Black/White wire at harness connector. If battery voltage exists, go to next step. If battery voltage does not exist, repair open in Black/White wire. 3.Raise and support vehicle with drive wheels off ground. Start engine. Shift transmission to Drive. Check for AC voltage between Purple/White and Light Green/Black wires of harness connector. 4.Voltage should change as wheel speed increases or decreases. If AC voltage does not exist, check for short or open in Purple/White and Light Green/Black wires. If wiring is okay, replace vehicle speed sensor. 5.Turn ignition off. Reconnect VSS buffer. Start engine. Put transmission into gear. Backprobe Blue/Black and Black/White wires at VSS buffer connector. If AC voltage varies with RPM change, replace VSS buffer. 6.Backprobe Red/White and Black/White wires at VSS buffer connector. If AC voltage varies with RPM change, replace VSS buffer. If all foregoing checks are okay, replace instrument cluster.
Vehicle speed sensor buffer receives and conditions AC voltage pulses, then sends them to cruise control module, Powertrain Control Module (PCM) and speedometer. Buffer is located behind instrument panel, above glove box.
Friday, April 16th, 2010 AT 7:35 PM