The Instrument Panel Cluster (IPC) provide the driver with indicator illumination. The Indicators may be illuminated internally or externally. Internally controlled indicators are directly controlled by the IPC. The IPC provides both power and ground to illuminate these indicators. When a particular system requires an indicator to illuminate, a message sent on the serial data line to the IPC to illuminate that indicator. When the IPC receives that message on the serial data line, the IPC will respond by illuminating the requested indicator. Externally controlled indicators are not directly controlled by the IPC. When a particular system or component requires an indicator to illuminate, then that system or component will provide the ground to illuminate that indicator. The IPC does not have direct control over these indicators, but may be responsible for bulb check illumination of these indicators.

The RH or LH turn indicators are externally controlled. The IPC illuminates these indicators when a direct LH or RH turn signal input is received from the turn signal switch. The IPC provides the ground and the turn signal switch provides the power for illumination.

The high beam indicator is externally controlled by the high beam switch. The IPC illuminates this indictor when the high beams are ON or when the "flash to pass" feature is activated. The IPC provides the ground and the high beam switch provides the power for illumination.

The seat belt indicator is external controlled by the seat belt switch. The IPC illuminates this indicator when the seat belts are not fastened. The IPC provides power and the seat belt switch provides the ground for illumination.

The air bag warning indicator is internally controlled by the IPC. The IPC illuminates this indicator for bulb check or when the IPC receives an indicator illumination request message on the serial data line from the SDM. The IPC provides power and ground to illuminate this indicator.

The brake indicator is externally controlled by the park brake and brake fluid level switch. The IPC illuminates this indicator when the park brake is applied, low brake fluid level condition exists or for bulb check. The IPC provides power and the park brake and brake fluid level switch provides the ground for illumination.

The CHECK GAGES indicator is internally controlled by the IPC. The IPC illuminates this indicator when the IPC detects a gauge perimeter has exceeded normal operating range, bulb check, or when a sudden drop in RPM (stall condition RPM = 0) has occurred with the ignition in the run position. The IPC provides power and ground to illuminate this indicator.

The ABS indicator is internally controlled by the IPC. The IPC illuminates this indicator for bulb check or when IPC receives an indicator illumination request message on the serial data line from the ABS system. The IPC provides power and ground to illuminate this indicator.

The MIL indicator is externally controlled by the PCM. The IPC illuminates this indictor when the PCM determines that a engine control malfunction exists. The IPC provides the power and the PCM provides the ground for illumination.

The SECURITY indicator is internally controlled by the IPC. The IPC illuminates this indicator for bulb check or when IPC receives an indicator illumination request message on the serial data line from the BCM. The IPC provides power and ground to illuminate this indicator.

The km/h (MPH) indicators are internally controlled by the IPC. The MPH and km/h indicators are illuminated by the IPC to indicate which scale of measurement the IPC is currently displaying (English or Metric). The IPC receives a direct input from the DIC switch to change the status from Km/h to MPH. The IPC provides power and ground to illuminate these indicators.

The traction control indicator is internally controlled by the IPC. The IPC illuminates this indicator for bulb check or when IPC receives an indicator illumination request message on the serial data line from the ABS system. The IPC provides power and ground to illuminate this indicator.

The 1 to 4 shift indicator is externally controlled by the PCM. The 1 to 4 shift indicator is used on 6 speed manual transmission vehicles for increased fuel economy. The IPC illuminates this indicator when the PCM determines that a 1 to 4 sift is necessary. The IPC provides power and the PCM provides the ground for illumination.