How to diagnose and fix a Jeep Speedometer doesn’t work problem
If you own an early 2000 Jeep and run into an issue where the Jeep Speedometer doesn’t work this post may help you diagnose and fix the problem.
The first step, as always, is to read the trouble codes. Most likely you’ll find a P0500 No Vehicle Speed Sensor Signal. Don’t automatically assume that means you should replace the transmission input and output speed sensors. Start by determining whether your vehicle was equipped with ABS brakes because Chrysler uses two different systems to calculate vehicle speed depending on which system is in your vehicle.
If your Jeep does NOT have ABS, then the speedometer gets its information from a vehicle speed sensor mounted in the top of the differential. The signal goes to the body control module (BCM) and is calculated based on the vehicle’s programmed axle ratio/tire size (electronic pinion factor). It transmits that information to the Powertrain Control Module (PCM) which sends it to the speedometer.
If the Jeep DOES have ABS, then the vehicle speed is determined by the wheel speed sensors. The signal goes to the Controller Antilock Brake (CAB) module which then transmits the information to the Body Control Module (BCM). The BCM sends the signal to the Powertrain Control Module (PCM). The PCM sends the information to the Speedometer via the Information Bus.
To diagnose Jeep speedometer doesn’t work issue, check the vehicle speed sensor and wiring harness at the differential (no ABS) or the wheel speed sensors (with ABS). In many cases you find the problem right away due to a visual harness rub through, broken wire, or connector issue. If you find a harness issue, order a replacement pigtail from Chrysler
©, 2016, Rick Muscoplat