Instrument Cluster Description and Operation: Odometer

WARNING: This page is about a different car, the 2009 Pontiac Torrent and 2009 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.

The odometer shows how far the vehicle has been driven, in either miles (domestic) or kilometers (export). The odometer is shown on display when any of the following occur:

Ignition is in ACC
Ignition is in RUN, with no messages on
The trip reset stem is pressed with the ignition OFF

Odometer readings are displayed in the IPC based on serial data message from the BCM. The ECM calculates the distance traveled from the vehicle speed sensor (VSS) input. The BCM receives a serial data message from the PCM and stores the current mileage.

The IPC stores the last valid odometer reading from the BCM in non-volatile memory. When a new valid odometer reading is received from the BCM, the IPC will update the display and store the new reading.

The IPC also receives serial data messages from the BCM regarding VIN and Vehicle content information. Valid information is stored in non-volatile memory at the first key-up with a new IPC. If the VIN or option content do not match the stored information, the odometer will display ERROR.