Suspension Control System - Suspension Damping Cadillac XLR I

Fastener Tightening Specifications

Fastener Tightening Specifications

Suspension Controls Schematic Icons

Suspension Controls Schematic Icons Icon Icon Definition IMPORTANT: Twisted-pair wires provide an effective shield that helps protect sensitive electronic components from electrical interference. If the wires were covered with shielding, install new shielding. In order to prevent electrical interference from degrading the performance of the connected components, you must maintain the proper specification when making any repairs to the twisted-pair wires shown : The wires must be twisted a minimum of 9 turns per 31 cm (12 in) as measured anywhere along the length of the wires The outside diameter of the twisted wires must not exceed 6.0 mm (0.25 in)

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Suspension Controls Connector End Views

Electronic Suspension Control (ESC) Module C1

Scheme 6

Suspension Controls Connector End Views

Electronic Suspension Control (ESC) Module C2

Scheme 7

Suspension Controls Connector End Views

Electronic Suspension Control (ESC) Module C3

Scheme 8

Scheme 9

Suspension Controls Connector End Views

Suspension Damper - LF

Suspension Damper - LR

Suspension Controls Connector End Views

Suspension Damper - LR

Suspension Damper - RF

Suspension Controls Connector End Views

Suspension Damper - RF

Suspension Damper - RR

Suspension Controls Connector End Views

Suspension Damper - RR

Scheme 10

Suspension Controls Connector End Views

Suspension Position Sensor - LF

Suspension Position Sensor - LR

Suspension Controls Connector End Views

Suspension Position Sensor - LR

Suspension Position Sensor - RF

Suspension Controls Connector End Views

Suspension Position Sensor - RF

Suspension Position Sensor - RR

Suspension Controls Connector End Views

Suspension Position Sensor - RR

Diagnostic Code Index

DIAGNOSTIC CODE INDEX

Diagnostic Starting Point - Electronic Suspension Control

Begin the system diagnosis with Diagnostic System Check - Vehicle . The Diagnostic System Check - Vehicle will provide the following information

1. The identification of the control modules which command the system
2. The ability of the control modules to communicate through the serial data circuit
3. The identification of any stored DTCs and their status

The use of the Diagnostic System Check - Vehicle will identify the correct procedure for diagnosing the system and where the procedure is located.

Scan Tool Output Controls

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 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.

Suspension Control Module

Scan Tool Data List

The 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

1. There is no published DTC procedure nor published symptom procedure for the customer concern.
2. 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

ESC Scan Tool Data Definitions

The ESC Scan Tool Data Definitions contain a brief description of all the scan tool parameters. This list is in alphanumeric order.

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit/System Description

The electronic suspension control module (ESCM) detects an internal malfunction.

Conditions for Running the DTC

The ignition is in the RUN position.

Conditions for Setting the DTC

An internal ESCM malfunction exists.

Action Taken When the DTC Sets

One or more of the following actions may occur

1. The ESC system is disabled.
2. The SERVICE SUSPENSION SYS and SPEED LIMITED message is displayed.

Conditions for Clearing the DTC

1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
2. The ESCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. The DTC can be cleared with a scan tool.

Circuit/System Verification

Verify DTC C0550 is not current.

1. If DTC C0550 is current, replace the ESCM.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ESCM replacement, setup, and programming

Circuit Description

The electronic suspension control (ESC) module performs checks of internal calibration data. If a fault condition is detected, the ESC module will set the fault DTC, and may, depending upon the fault type, turn on the SERVICE SUSPENSION SYSTEM message. Recovery from any controller fault condition is attempted only after the ignition is cycled ON and OFF.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC C0558 Calibration Data Not Programmed

The ignition is ON.

1. The DTC is set when any calibration faults internal to the ESC module are detected.
2. The fault is detected during 3 consecutive ignition cycles, or during the same ignition cycle after clearing the DTC with the scan tool.

1. Disable all functionality.
2. Sends a message to the instrument panel cluster (IPC) to display the SERVICE SUSPENSION SYSTEM message.

Conditions for Clearing the MIL/DTC

1. The scan tool can be used to clear the DTC.
2. The DTC is saved as HISTORY when the ESC module no longer senses the hardware fault and the ignition is cycled OFF and ON.

Test Description

The number below refers to the step number on the diagnostic table.

1. 2: This step checks to see if the problem has cleared after the ESC module has been calibrated.

DTC C0558

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

The electronic suspension control module (ESC) module commands variable levels of pulse width modulated current to each damper in response to rough road, or abrupt steering maneuver driving conditions. The ESC module continuously compares each dampers command state with the state of their feedback circuits to ensure they agree.

Ignition ON for 30 seconds.

The damper coil or the circuits to the coil are shorted to ground, shorted to voltage, or open for 3 consecutive ignition ON cycles.

1. The instrument panel cluster displays the SERVICE SUSPENSION SYSTEM message.
2. If the DTC symptom 01 is stored, the electronic suspension control (ESC) system is disabled.
3. If the DTC symptom 02 or 04 is stored, the suspect damper is disabled.

1. A current DTC will clear on the next consecutive malfunction-free ignition cycle.
2. A history DTC will clear after 50 consecutive malfunction-free ignition cycles.

Diagnostic Aids

1. Before proceeding with the diagnostics, ensure the electrical harness connector at the suspect damper is fully engaged by pushing the harness connector toward the damper. If an audible click is heard, or substantial engagement travel is noted, ensure the remaining damper connectors are fully engaged as well.
2. When the scan tool is used to clear the DTC, the ESCMs ignition cycle counter is disabled for the remainder of the ignition cycle. This allows the DTC to set upon initial malfunction detection. Once the ignition is cycled the counter resets to 3.
3. The scan tool can be used to command the suspect damper On and Off while actuating the suspension and noticing an increase and decrease in damping control.

Reference Information

Schematic Reference

Suspension Controls Schematics

Connector End View Reference

Suspension Controls Connector End Views

Description and Operation

Electronic Suspension Control Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

Scan Tool Reference

1. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/electronic-suspension/#suspension-control-system-suspension-damping__scan-tool-output-controls)
2. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/electronic-suspension/#suspension-control-system-suspension-damping__scan-tool-data-list)
3. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/electronic-suspension/#suspension-control-system-suspension-damping)

Ignition ON, command the damper actuator ON and OFF while jouncing the vehicle in the front and rear. Suspension should change stiffness when commanded between the ON and OFF state.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the applicable suspension damper.
2. Test for less than 1.0 ohm of resistance between the low reference circuit terminal and ground. If greater than 1.0 ohm, test the low reference circuit for an open/high resistance.
3. Connect a test lamp between the control circuit terminal and the ground circuit terminal.
4. Command the applicable damper ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the ESC module. If the test lamp is always OFF, test for a short to ground or an open/high resistance on the control circuit. If the circuit tests normal, replace the ESC module.
5. If all circuits test normal, test or replace the applicable suspension damper.

Component Testing

1. Ignition OFF, disconnect the harness connector at the applicable suspension damper.
2. Test for less than 2 ohms of resistance between the control circuit terminal and the low reference circuit terminal of the applicable suspension damper. If not within the specified range, replace the applicable suspension damper.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Shock Absorber Replacement (W/F55)»(/cadillac/xlr/i-2003-2009/remont/suspension-front/#front-suspension-system__shock-absorber-replacement-wf55)
2. «Shock Absorber Replacement (W/F55)»(/cadillac/xlr/i-2003-2009/remont/suspension-rear/#rear-suspension-system)
3. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ESC replacement, setup, and programming.

The electronic suspension control (ESC) module supplies 5 volts to the position sensors. The position sensors use the supplied 5 volts to produce an analog output range of 0-5 volts. The ESC module calculates vehicle suspension settings based upon the voltage levels received back from the position sensors. The ESC model monitors for an out of range condition.

DTC Descriptors

This diagnostic procedure supports the following DTCs

1. DTC C0615 Left Front Position Sensor Circuit
2. DTC C0620 Right Front Position Sensor Circuit
3. DTC C0625 Left Rear Position Sensor Circuit
4. DTC C0630 Right Rear Position Sensor Circuit

DTC C0615, C0620, C0625 or C0630

1. The ignition is ON.
2. The ESC function is enabled.

1. The ESC module senses position sensor output voltage under 0.35 or over 4.75 volts.
2. The condition must be detected for 1 second in 4 consecutive ignition cycles.
3. No activity on the position sensor when activity detected on 2 or more other position sensors.

1. Stores a DTC C0615, C0620, C0625, or C0630 in the ESC memory.
2. Command speed dependent damping system default AND command normal force signals to default state.
3. Sends a message to the instrument panel cluster (IPC) to display the SERVICE SUSPENSION SYSTEM message.

1. The ESC module senses the correct position sensor output voltage between 0.35-4.75 volts.
2. A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
3. Use the IPC clearing DTC feature.
4. Using a scan tool

1. The following conditions may cause an intermittent malfunction to occur: There is an intermittent open or short in the position sensor circuit. Bent, disconnected, or damaged position sensor linkage.
2. When using a scan tool in order to read position sensor voltage, always make sure the vehicle is sitting with the full vehicle weight on its wheels. Measuring position sensor voltage with the vehicle raised and the wheels hanging may lead to incorrect diagnosis.
3. An intermittent DTC C0615, C0620, C0625 or C0630 may produce a random firm/soft ride condition.
4. The ESC module uses an ignition cycle counter diagnosis approach to set this DTC. This requires the ESC module to detect a malfunction 4 times before setting the DTC. To disable this feature, use a scan tool to clear all DTCs before performing diagnosis procedures.
5. If the DTC is a history DTC, the problem may be intermittent. Using a scan tool, monitor the position sensor voltage while test driving the vehicle or moving the wiring and connectors. This can often cause the malfunction to occur.

If the left front position sensor DTC symptom was 08 then allow 30 seconds for redetection following clear codes.

If the left front position sensor DTC symptom was 55 then redetection requires driving the vehicle.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: This step tests the position sensor signal voltage range using a scan tool. Normal signal voltage is between 1.5-3.5 volts.
2. 3: This step tests the position sensor signal voltage range using a scan tool with the sensor disconnected. Normal signal voltage range with the sensor disconnected is approximately 0 volts.
3. 4: This step tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
4. 5: This step tests for a short to voltage in the 5-volt reference circuit.
5. 6: This step tests for high resistance or an open in the ground circuit.
6. 11: This step tests for an open or high resistance in the position sensor ground circuit.

DTC C0615, C0620, C0625 or C0630

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

The electronic suspension control (ESC) module controls the dampers through the use of an internal relay. These relays are internal to the module and are not serviced separately.

Ignition ON

An internal damper relays fault is detected within the ESC module

All ESC functions are disabled

1. A current DTC will clear when the fault is no longer present
2. A history DTC will clear after 50 malfunction free ignition cycles

Schematic Reference

Suspension Controls Schematics

Connector End View Reference

Suspension Controls Connector End Views

Description and Operation

Electronic Suspension Control Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

Ignition ON, verify that DTC C0690 is not set as current.

1. If DTC C0690 is set as current, replace the ESC module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ESC module replacement, setup, and programming

The electronic suspension control (ESC) module provides a common regulated power supply of about 5 volts to all of the position sensors. The ESC module monitors this power supply for a malfunction that could prevent it from correctly regulating the supply voltage.

This diagnostic procedure supports the following DTC

DTC C0696 Position Sensor Overcurrent (5-volt supply)

The ignition is ON.

1. The ESC module senses position sensor supply voltage under 4.5 volts or over 5.5 volts.
2. The condition must be detected for 1 second in 4 consecutive ignition cycles.

1. Stores a DTC C0696 in the ESC memory
2. Command speed dependent damping system default AND command normal force signals to default state.
3. Sends a message to the instrument panel cluster (IPC) to display the SERVICE SUSPENSION SYSTEM message

1. A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
2. The ESC module senses the correct sensor supply voltage (4.5-5.5 volts).
3. The IPC clearing DTCs feature
4. Using a scan tool

1. The following conditions may cause an intermittent malfunction to occur: An intermittent short to ground is detected on any of the position sensor supply circuits. An intermittent short to voltage is detected on any of the position sensor supply circuits.
2. The ESC module uses a common power supply in order to provide voltage to all of the position sensors. Therefore, a position sensor overcurrent code may be set if a malfunction is detected on any position sensor supply circuit.
3. The ESC module uses an ignition cycle counter diagnostic approach to set this DTC. This requires the ESC module to detect the malfunction 4 times before setting the DTC. To disable this feature, use a scan tool to clear all DTCs before preforming diagnostic procedures.
4. If any position sensor supply circuit is shorted to ground, the scan tool will indicate all of the position sensor voltage readings as zero.
5. If any position sensor is shorted to voltage, the position sensor will still function properly and the scan tool will display a valid position sensor voltage reading.
6. An intermittent DTC C0696 may produce a random firm/soft condition.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: This tests the position sensor signal voltage range using a scan tool. The scan tool will display 0 volts for all position sensors if any position sensor 5-volt reference circuit is shorted to ground.
2. 3: This tests if any position sensor is shorted to ground.
3. 4: This tests determines which position sensor is shorted to ground.
4. 5: Tests for a short to ground in the position sensor 5-volt reference circuits.
5. 6: Tests for a short to voltage in the position sensor 5-volt reference circuits.

DTC C0696

Voltage is supplied to the electronic suspension control (ESC) module in the battery positive voltage circuit and the ignition voltage circuit. The ESC module monitors the supplied voltage to determine if it is within a valid operating range.

This diagnostic procedure supports the following DTC

DTC C0895 Device Voltage

The ignition is ON.

The DTC is set when the battery voltage is outside the normal range of 9-15.5 volts.

Disable All Functionality

1. The scan tool can be used to clear the DTC.
2. The DTC is saved as history when the ESC module no longer sees battery voltage outside the normal range of 9-15.5 volts. The DTC will clear if the fault does not return after 50 consecutive ignition cycles.

DTC C0895 may set when the vehicle is placed on a battery charger, on fast charge, for a long period of time. It may also be set by an intermittent charging system malfunction.

The numbers below refer to the step numbers on the diagnostic table.

1. 1: This test determines whether the malfunction is in the supply voltage or the ESC module.
2. 2: Checks for high resistance, a short to ground, or an open in the battery positive voltage circuit.

DTC C0895

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Voltage is supplied to the electronic suspension control (ESC) module in the battery positive voltage circuit and the ignition voltage circuit. The ESC module monitors the supplied voltage to determine if it is within a valid operating range.

The ignition is ON

Battery voltage is outside the normal range of 9-15.5 volts

All ESC functions are disabled

1. A current DTC will clear when the fault is no longer present
2. A history DTC will clear after 50 fault free ignition cycles

Schematic Reference

Suspension Controls Schematics

Connector End View Reference

Suspension Controls Connector End Views

Description and Operation

Electronic Suspension Control Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

1. Ignition OFF, disconnect the harness connector at the ESC module.
2. Test for less than 5 ohms of resistance between the ground circuit terminal 2 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, test for 9-15.5 volts between the B+ circuit terminal 1 and ground. If less than the specified range, test the B+ circuit for a short to ground or an open/high resistance. If greater than the specified range, refer to «Charging System Test»(/cadillac/xlr/i-2003-2009/remont/charging-system/#battery-charging-system-and-starting-system__charging-system-test) .
4. Test for 9-15.5 volts between the ignition circuit terminal 19 and ground. If less than the specified range, test the ignition circuit for a short to ground or an open/high resistance. If greater than the specified range, refer to «Charging System Test»(/cadillac/xlr/i-2003-2009/remont/charging-system/#battery-charging-system-and-starting-system__charging-system-test) .
5. If all circuit test normal, replace the ESC module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ESC module replacement, setup, and programming

Symptoms - Electronic Suspension Control

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the electronic suspension control (ESC) system. Refer to «Checking Aftermarket Accessories»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__checking-aftermarket-accessories) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
3. Inspect the connectors to be properly seated and free of corrosion.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

Soft and Non-Uniform Ride

Soft and Non-Uniform Ride

Soft and Non-Uniform Ride

Scheme 11

Electronic Suspension Control Module Replacement

Removal Procedure

1. Turn OFF the ignition switch.
2. Raise the vehicle on a suitable safety stand. Refer to «Lifting and Jacking the Vehicle»(/cadillac/xlr/i-2003-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
3. Remove the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/xlr/i-2003-2009/remont/wheel-tire-system/#tires-and-wheels) .
4. Disconnect the electronic suspension control (ESC) position sensor harness connector.
5. Remove the position sensor link from the control arm link stud.
6. Remove the position sensor mounting bolts.
7. Remove the position sensor from the vehicle.

Installation Procedure

1. Install the position sensor in the vehicle.
2. Install the position sensor mounting bolts. Tighten: Tighten the bolts to 3 N.m (26 lb in).
3. Install the position sensor link to the control arm link stud.
4. Connect the ESC position sensor harness connector.
5. Install the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/xlr/i-2003-2009/remont/wheel-tire-system/#tires-and-wheels) .
6. Lower the vehicle.

1. Turn OFF the ignition switch.
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/xlr/i-2003-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
3. Remove the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/xlr/i-2003-2009/remont/wheel-tire-system/#tires-and-wheels) .
4. Disconnect the electronic suspension control (ESC) position sensor harness connector.
5. Disconnect the position sensor link from the control arm link stud.
6. Remove the position sensor mounting bolt.
7. Remove the position sensor from the vehicle.

1. Install the position sensor to the vehicle.
2. Install the position sensor mounting bolt. Tighten: Tighten the bolt to 7 N.m (62 lb in).
3. Connect the position sensor link to the control arm link stud.
4. Connect the ESC position harness connector.
5. Install the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/xlr/i-2003-2009/remont/wheel-tire-system/#tires-and-wheels) .
6. Lower the vehicle.

Electronic Suspension Control Description

The Electronic Suspension Control system is a Magneto-Rheological Real Time Damping (MRRTD) system and independently controls the fluid viscosity in each strut and shock absorbers to control the vehicle ride characteristics.

The following are involved in the operation of the ESC system

1. Electronic suspension control module (ESCM) - Controls and detects failures in the ESC system. The ESCM controls the damping force at all 4 shock absorbers individually for a soft or firm ride. It receives inputs from vehicle speed, steering wheel position, suspension position, and lift/dive status to determine the amount of damper control to the shocks electrical coil.
2. Front/rear suspension position sensors - The ESC module provides a 5-volt reference and low reference to all 4 of the body-to-wheel suspension position sensors. The sensors send the ESCM a signal voltage that is relative to the suspension ride height used to determine the amount of damper control. The sensors valid range is 0.35-4.75 volts.
3. Front struts/rear shock absorbers have an internal electrical coil, and micron sized metal particles in the fluid.
4. Vehicle speed-The ESCM receives a serial data message for vehicle speed input, and is used to determine the amount of damper control.
5. Steering wheel position-The ESCM receives a serial data message for steering wheel position input and uses this as an indication of the position and rotation of the steering wheel to determine the amount of damper control.

The ESCM monitors the inputs from the front/rear suspension position sensors, vehicle speed, and steering wheel position. The ESCM calculates the inputs to control 0-100 percent of PWM current to the coil within each strut or shock, increasing the fluids viscosity by aligning the metal particles with each other. This increases or decreases the suspension damping force in both compression and rebound directions.

When the ESCM detects a malfunction and sets a DTC. The system disables, and defaults with a fail-soft action, then sends a serial data message for the Instrument Panel Cluster (IPC) to display service suspension system and speed limited to 80 mph warning messages.

The ESC system uses an ignition cycling diagnostic approach in order to reduce the occurrence of false or intermittent DTCs that do not affect the functionality of the ESC system. This allows the fail-soft actions to be taken whenever a malfunction condition is current, but requires the malfunction to be current for 3 consecutive ignition on cycles before the corresponding malfunction code and message will be stored or displayed.

Special Tools

Special Tools Illustration Tool Number/Description J 35616-A Connector Test Adapter Kit J 39200 Digital Multimeter J 42236-A Serial Data Link Tester J 34142-B Test Light 7000081 Tech 2 Kit

Scheme 12

Scheme 13

Scheme 14

Scheme 15

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Diagnostic Repair Verification
• Control Module References
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Shock Absorber Replacement (W/F55)
• Shock Absorber Replacement (W/F55)
• Battery Inspection/Test
• Charging System Test
• Checking Aftermarket Accessories
• Lifting and Jacking the Vehicle
• Wheelhouse Filler Replacement
• Tire and Wheel Removal and Installation
• Fastener Notice
• DTC C0550
• Scan Tool Output Controls
• Scan Tool Data List
• Soft and Non-Uniform Ride