GM Service Manual Online
For 1990-2009 cars only

The electronic suspension control (ESC) Scan Tool Data List contains all the electronic suspension control system related parameters that are available on the scan tool. The parameters in the list are arranged in alphabetical order. The column, "Data List," indicates the location of the parameter within the scan tool menu selections.

Use the ESC Scan Tool Data List as directed by a diagnostic table or in order to supplement the diagnostic procedures. Begin all of the diagnostic procedures with the Vehicle Diagnostic System Check.

Use the ESC Scan Tool Data List only after the following is determined:

    • There is no published DTC procedure nor published symptom procedure for the customer concern.
    • The DTC or symptom diagnostic procedure indicated by the diagnostic system check does not resolve the customer concern.

The Typical Data Values are obtained from a properly operating vehicle under the conditions specified in the first row of the Scan Tool Data List table. Comparison of the parameter values from the suspect vehicle with the Typical Data Values may reveal the source of the customer concern.

A scan tool must be used in diagnosing system malfunctions before removing or replacing any of the components. Become familiar with the scan tool diagnostic capabilities and thoroughly understand each of the diagnostic features described before attempting any diagnostic procedures. The scan tool is capable of displaying data and input/output information from all of the systems connected to the serial data line. The scan tool is also capable of commanding the shock absorbers ON or OFF without the need for any input information.

Data Display

The scan tools input display function can be helpful in determining if the ESC module is receiving the correct input status. This can assist in determining if the ESC system is actually operating normally. For example, the ESC system requires the input from the position sensors in order to determine the ride settings. A starting point might be to select the LF position sensor data display function from the scan tool menu. The voltage status should change when the LF corner of the car is pressed down and released. If no change occurred, then the problem is possibly a disconnected link or a stuck sensor. If change did occur, then the problem is intermittent. In order to diagnose this condition using a scan tool, watch the data display for the LF position sensor while moving the suspected wiring/connector. Try to duplicate the malfunction conditions. This scan tool feature allows checks that could not be performed while driving the vehicle.

ESC Scan Tool Data List

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Turn the Ignition ON, Engine OFF/Vehicle Trim Height within Specifications

Battery Voltage Signal

--

Volts

B+

LF Damper Actuator Command

--

0-100%

0-90%

LF Position Sensor

--

0-5 Volts

1.5-3.5 Volts

LR Damper Actuator Command

--

0-100%

0-90%

LR Position Sensor

--

0-5 Volts

1.5-3.5 Volts

RF Damper Actuator Command

--

0-100%

0-90%

RF Position Sensor

--

0-5 Volts

1.5-3.5 Volts

RR Damper Actuator Command

--

0-100%

0-90%

RR Position Sensor

--

0-5 Volts

1.5-3.5 Volts

Vehicle Speed

--

km/h (mph)

Varies