Fix Instrument Cluster on a Jeep
This Instrument Cluster Jeep tech tip should come under the heading, “what were those engineers smoking when they designed this system?” These vehicles use a data bus that allows several computers to exchange digital data. The computers that talk to one another are: the body control module (BCM) electronic vehicle information center (EVIC), controller anti-lock brake (CAB), the radio, driver door module (DDM), passenger door module (PDM), automatic temperature control module (ATC), airbag control module (ABCM), powertrain control module (PCM), and the instrument cluster.
Technically speaking the BCM should have nothing to do with the operation of the gauges on the instrument cluster. But if you run a voltage check on the power and ground wires to the BCM and come up with 0 volts, here’s where to head next. The BCM gets its power from the power distribution center (PDC) located under the hood. The power feed wire comes out of the PDC and enters a splice near the battery temperature sensor. (The sensor detects battery temperature and the PCM uses that to help determine charging rate and prevent battery overheating due to overcharging.) Since the splice and sensor are located next to the battery, the splice can, you guessed it, corrode from battery acid.
If you find corrosion at that splice, take it apart and resolder it. That should provide power to the BCM and eliminate the dead cluster.
© 2012 Rick MuscoplatPosted on by Rick Muscoplat