| Table 1: | Suspension Control Module |
A scan tool may be used in order to command the shock absorbers ON or OFF, without the need for input information from other components. This can be very helpful in determining if a certain portion of a circuit or a component is in working order. The table below lists the tests that are available for the electronic suspension control system. The tests are listed in alphabetical order.
Using a Tech2 Scan tool, select the ESC Special Functions from the scan tool menu. The status of the output being cycled will be shown on the scan tool's display screen. The shock absorbers can be cycled to turn ON or OFF by selecting ESC Special Functions on the scan tool.
Using the LF shock absorber as an example, commanding the LF shock absorber ON can indicate whether the ESC system is able to correctly operate the LF shock absorber. This can determine if a DTC that pertains to that shock absorber is able to reset, and if the ESC module's internal circuitry is able to operate the LF shock absorber. For example, suppose the ESC system sets an intermittent DTC C0577, which is LF Shock Absorber Solenoid Short to Ground. In order to diagnose this condition using a scan tool, select the ESC special Functions. Then, cycle the LF shock absorber solenoid while moving the suspected wiring/connector. Attempt to duplicate the malfunction conditions. This scan tool feature allows checks that could not be performed while driving the vehicle. This example can be applied to the other shock absorbers.
Scan Tool Output Control | Additional Menu Selection(s) | Description |
|---|---|---|
All Command | -- | Commands the shock solenoids ON and OFF. |
LF Damper Actuator Command | -- | Commands the left front shock solenoid ON and OFF. |
LR Damper Actuator Command | -- | Commands the left rear shock solenoid ON and OFF. |
RF Damper Actuator Command | -- | Commands the right front shock solenoid ON and OFF. |
RR Damper Actuator Command | -- | Commands the right rear shock solenoid ON and OFF. |
The Electronic Suspension Control Module 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 Electronic Suspension Control Module 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 Electronic Suspension Control Module 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 Electronic Suspension Control Module 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 Electronic Suspension Control module is receiving the correct input status. This can assist in determining if the Electronic Suspension System is actually operating normally. For example, the Electronic Suspension Control 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.
Parameter | Operating Conditions | Expected Value | Definition |
|---|---|---|---|
Ignition is ON, engine OFF, and vehicle is stationary on level ground. | |||
Battery Voltage | 12-14V | Volts | The scan tool displays 0-14 Volts. The scan tool displays approximately 12 Volts when the ignition is ON. |
Ignition Voltage Signal | IGN Switch ON | Active | Ignition voltage signal should follow IGN switch under normal conditions. |
IGN Switch OFF | Inactive | ||
Suspension Control Select Switch | Button Pressed | On | Momentary switch. Pulls to Ground signalling module to alter activation rate. |
Button Not Pressed | Off | ||
Suspension Control Indicator | SEN / GTS | On | Mode Indicator located within Switch. |
SEN / GTS | Off | ||
Suspension Control Selection Indicator | N/A | N/A | N/A |
N/A | N/A | ||
Service Suspension Control Indicator | DTC / Problem Raised | On | Service Suspension Control Indicator is only illuminated if a DTC is registered or a malfunction has occurred. |
Normal Operation | Off | ||
Vehicle Speed | 0 Km/h when Vehicle is stationary. | Kph Mph | The scan tool displays 0-255 km/h (0-159 mph). The ESC system obtains vehicle speed data from the PCM on a dedicated input. The PCM is responsible for calculating the correct vehicle speed data. |
Right Front Position Sensor | 0 - 5.0V | 1.5-3.5 Volts | This parameter displays the position sensor is a variable resistor which changes with vehicle trim height. The ESC system adjusts the damping level in each shock absorber based upon the voltage level received back from all four sensors. |
Right Front Damper Actuator Command | 0 - 100 | 0% | This parameter displays the commanded state of the shock absorber solenoid. When the ESC special functions is selected on the scan tool menu and the shock solenoid is commanded ON, the percentage will increase. When the shock solenoid is commanded OFF the percentage will decrease. |
Left Front Position Sensor | 0 - 5.0V | 1.5-3.5 Volts | This parameter displays the position sensor is a variable resistor which changes with vehicle trim height. The ESC system adjusts the damping level in each shock absorber based upon the voltage level received back from all four sensors. |
Left Front Damper Actuator Command | 0 - 100 | 0% | This parameter displays the commanded state of the shock absorber solenoid. When the ESC special functions is selected on the scan tool menu and the shock solenoid is commanded ON, the percentage will increase. When the shock solenoid is commanded OFF the percentage will decrease. |
Right Rear Position Sensor | 0 - 5.0V | 1.5-3.5 Volts | This parameter displays the position sensor is a variable resistor which changes with vehicle trim height. The ESC system adjusts the damping level in each shock absorber based upon the voltage level received back from all four sensors. |
Right Rear Damper Actuator Command | 0 - 100 | 0% | This parameter displays the commanded state of the shock absorber solenoid. When the ESC special functions is selected on the scan tool menu and the shock solenoid is commanded ON, the percentage will increase. When the shock solenoid is commanded OFF the percentage will decrease. |
Left Rear Position Sensor | 0 - 5.0V | 1.5-3.5 Volts | This parameter displays the position sensor is a variable resistor which changes with vehicle trim height. The ESC system adjusts the damping level in each shock absorber based upon the voltage level received back from all four sensors. |
Left Rear Damper Actuator Command | 0 - 100 | 0% | This parameter displays the commanded state of the shock absorber solenoid. When the ESC special functions is selected on the scan tool menu and the shock solenoid is commanded ON, the percentage will increase. When the shock solenoid is commanded OFF the percentage will decrease. |
Lift / Drive Status | N/A | Neutral | Will not change while vehicle is stationary. |
Lift / Drive Change | -- | Unchanged | Will not change while vehicle is stationary. |
Test Normal Force Left Rear | -- | On | Will not change while vehicle is stationary. |
-- | Off | ||
Test Normal Force Right Rear | -- | On | Will not change while vehicle is stationary. |
-- | Off | ||
Test Normal Force Left Front | -- | On | Will not change while vehicle is stationary. |
-- | Off | ||
Test Normal Force Right Front | -- | On | Will not change while vehicle is stationary. |
-- | Off | ||
Normal Force Left Front | 0 - 100 | 20% | -- |
Normal Force Right Front | 0 - 100 | 20% | -- |
Normal Force Left Rear | 0 - 100 | 20% | -- |
Normal Force Right Rear | 0 - 100 | 20% | -- |
