Instrument Panel Cluster (IPC) Description and Operation: Odometer

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 instrument panel cluster (IPC) based on a class 2 message from the body control module (BCM). The engine control module (ECM) calculates the distance traveled from the vehicle speed sensor (VSS) input. The BCM receives a controlled area network (CAN) serial data message from the ECM 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 class 2 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.