Auxiliary Gauges Description and Operation

Auxiliary Gauges Description and Operation

Engine Oil Pressure Gauge

The auxiliary gauge module displays the engine oil pressure as determined by the engine control module (ECM). The ECM sends the engine oil pressure information via a High Speed CAN-Bus signal to the body control module (BCM). The BCM then sends the information via a Low Speed CAN-Bus signal to the auxiliary gauge module to display the engine oil pressure. The engine oil pressure gauge defaults to 0 kPa (0 PSI) if:

* The ECM detects a malfunction in the engine oil pressure sensor circuit.

* The BCM detects a loss of serial data communications with the ECM.

* The auxiliary gauge module detects a loss of serial data communications with the BCM.

Engine Oil Temperature Gauge

The auxiliary gauge module displays the engine oil temperature based on the information from the ECM. The ECM converts the data from the engine oil temperature sensor to a engine oil temperature signal. The ECM sends the engine oil temperature signal via a High Speed CAN-Bus signal to the BCM. The BCM then sends the information via a Low Speed CAN-Bus signal to the auxiliary gauge module to display the engine oil temperature. The engine oil temperature gauge defaults to 40°C (100°F) if:

* The ECM detects a malfunction in the engine oil temperature sensor circuit.

* The BCM detects a loss of serial data communications with the ECM.

* The auxiliary gauge module detects a loss of serial data communications with the BCM.

Transmission Fluid Temperature Gauge

The auxiliary gauge module displays the transmission fluid temperature based on the information from the transmission control module (TCM) on an automatic transmission vehicle or from the engine control module (ECM) on an manual transmission vehicle. The ECM or the TCM sends the transmission fluid temperature information via serial data to the BCM. The BCM then sends the transmission fluid temperature information via serial data to the auxiliary gauge module in order to display the transmission fluid temperature. The transmission fluid temperature gauge defaults to 0°C (30°F) if:

* The ECM or the TCM detects a malfunction in the transmission fluid temperature sensor circuit.

* The BCM detects a loss of serial data communications with the ECM or the TCM.

* The auxiliary gauge module detects a loss of serial data communications with the BCM.

Volt Gauge

The auxiliary gauge module displays the battery voltage. This gauge shows the condition of the charging system. The vehicle charging system regulates voltage based on the state of charge of the battery. It is normal for the volt gauge to fluctuate. Readings between the low and high warning zones indicate the normal operating range. Readings in the low warning zone can occur when a large number of electrical accessories are operating in the vehicle and the engine is left idling for an extended period. If there is a problem with the battery charging system, a message appears in the driver information center display and/or the charging system telltale comes on.