Odometer: 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 in the top line of the message display when any of the following occur:
- Ignition is in adaptive cruise control (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)/powertrain control module (PCM) calculates the distance traveled from the vehicle speed sensor (VSS) input. The BCM receives a class 2 message from the ECM/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 class 2 messages from the BCM regarding vehicle identification number (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.