CNG Gauge

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

The Compressed Natural Gas (CNG) gauge gives an indication to the vehicle operator of the level of CNG in the tanks. This gauge is controlled by the instrument cluster circuit board based upon cluster programming and a bus message received by the cluster. This bus message is based upon a hard-wired input received by the Body Control Module (BCM) from the sending unit on the CNG tank.

The CNG gauge is a stepper motor design unit that receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the ON or START positions. The cluster is programmed to move the gauge needle back to the low end of the scale after the ignition switch is turned to the OFF position. The Instrument Panel Cluster (IPC) electronic circuitry controls the gauge needle position.