For 1990-2009 cars only
Use the scan tool data display values and definitions information in order to assist in diagnosing vehicle malfunctions. Compare the vehicles actual scan tool data with the typical data display value table information. Use the information in order to aid in understanding the nature of the concern when the vehicle data does not match the typical data display values.
The scan tool data values were taken from a known good vehicle under the following conditions:
| • | The ignition switch is in the ON position. |
| • | The engine is not running. |
| • | The vehicle is in PARK. |
Battery Voltage: This parameter displays the amount of battery voltage available to the body control module (BCM).
Currant Power Mode: This parameter displays the power mode defined by the power mode master and communicated to the modules that require this information. There are 4 possible display parameters depending on the ignition switch position. These are Off, Accessory, Run, and Crank Request. This parameter should match the actual ignition switch position.
HS Comm. Cmd.: The scan tool displays the commanded state of the serial data communication enable circuit output. The scan tool displays ON when the BCM provides voltage to the circuit. This voltage output acts as a wakeup signal for the electronic brake control module (EBCM).
Ign. Off/Run/Crank: The BCM uses this data input signal from the off/run/crank voltage circuit (1 of 3 circuits) in order to determine the power mode (ignition switch position). There are 4 possible display parameters depending on the ignition switch position. These are Key Out/Run, Key In/Off, Crank, or Run.
Ignition Accessory/Run: The BCM uses this data input signal from the accessory voltage circuit (1 of 3 circuits) in order to determine the power mode (ignition switch position). Active is displayed when the ignition switch is in the Accy or Run positions.
Ignition Run/Crank: The BCM uses this data input signal from the ignition 1 voltage circuit (1 of 3 circuits) in order to determine the power mode (ignition switch position). Active is displayed when the ignition switch is in the Run or Crank positions.
Key in Ignition Status: The scan tool displays the ignition key in/out status. The parameters are Key Out, and Key In.
Powertrain HS Comm. Cmd.: The scan tool displays the commanded state of the accessory wake up serial data circuit output. The scan tool displays ON when the BCM provides voltage to the circuit. This voltage output acts as a wakeup signal for the powertrain control module(s).
Run/Crank Relay Command: The scan tool displays the commanded state of the run/crank relay. The scan tool displays ON when the BCM provides voltage to the run/crank relay control circuit.
