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Electronic Chassis Control: Other Saab 9-4X I

Electronic Suspension 3 illustrations ~1590 words

Suspension Control Module

The suspension control module controls the system functions and detects failures. The suspension control module receives input information by vertical acceleration sensors that are directly connected to the module and by other systems through the serial data line. The suspension control module commands variable levels of current to each shock absorber actuator.

Vertical Acceleration Sensors

The suspension control module supplies a common 5 V reference and a ground circuit to each of the five vertical acceleration sensor. The vertical acceleration sensors supply a signal of 0.5-4.5 V to the suspension control module.

The three vertical body acceleration sensors are mounted left front, right front and rear. The two front vertical suspension acceleration sensors are mounted at the strut.

Shock Absorber Actuators

The shock absorber actuators are integrated within the shock absorbers. The electronic suspension control system uses a proportional valve that is located in the external bypass of the displacement module.

Adjustment is performed by current control. The current consumption is 0-1.8 A. The actuators respond to commands of the suspension control module within milliseconds.

Driver Information Center Message

The electronic suspension control system does not have a malfunction indicator, but uses the instrument cluster for the display functions instead. When the suspension control module detects a fault that sets a DTC, it sends a message on the serial data line to the instrument cluster, which will display the following message

SERVICE SUSPENSION SYSTEM

The suspension control module has the ability to store DTCs as current or history codes. Most electronic suspension control system malfunctions will display a message in the instrument cluster and set a DTC. As long as the DTC is present, the message will be displayed.

The suspension control module uses an ignition cycling diagnostic approach. Actions taken when a fault is detected will remain until the ignition is turned OFF, even if the fault condition is not present anymore.

If a fault is no longer present, the DTC will be stored as a history code. After 41 consecutive malfunction-free ignition cycles the DTC will be deleted.

Vehicle Leads/Pulls

StepActionYesNo
DEFINITION: At a constant highway speed on a typical straight road, lead/pull is the amount of effort required at the steering wheel to maintain the vehicle straight path.
1Did you review the General Description and perform the visual/physical inspections?Go to Step 2Go to SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS
2Road test the vehicle in order to verify the complaint. Does the vehicle operate normally?System OKGo to Step 3
3Inspect the tire/wheel assemblies for the following: Correct tire pressure-Refer to the TIRE PLACARD . Correct tire size-Refer to the TIRE PLACARD . Abnormal tire wear or damage Did you find and correct the condition?Go to Step 9Go to Step 4
4Perform the RADIAL TIRE LEAD/PULL CORRECTION . Did you find and correct the condition?Go to Step 9Go to Step 5
5Inspect and correct/adjust the suspension and steering systems for the following: Vehicle trim height-Refer to TRIM HEIGHT SPECIFICATIONS . Excessively worn, loose, or damaged components Did you find and correct the condition?Go to Step 9Go to Step 6
6Inspect the brake system for brake drag. With the vehicle suspended on a hoist, brake drag can be identified by rotating each wheel several times and observing whether more force is needed to rotate the left wheel or the right wheel. Did you find and correct the condition?Go to Step 9Go to Step 7
7Inspect the wheel alignment and adjust as necessary. Refer to WHEEL ALIGNMENT MEASUREMENT . Did you correct the condition?Go to Step 9Go to Step 8
8Inspect the steering gear for unequal effort. The vehicle must be suspended on a hoist, the engine running, and the transmission in park or neutral. Grasp the tire assembly and manually simulate a turn from the left of center and the right of center observing whether more force is needed to turn to the left or to the right. If this condition exists, replace the steering gear. Did you correct the condition?System OKGo to Step 3
9Operate the vehicle in order to verify the repair. Did you correct the condition?System OKGo to Step 3

Body Leans or Sways in Corners

StepActionYesNo
1Did you review the General Description and perform the necessary inspections?Go to Step 2Go to SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS
2Verify the vehicle leans or sways in corners. Does the vehicle operate normally?System OKGo to Step 3
3Inspect the following components for wear or damage: Rear coil springs Front coil springs Are the components worn or damaged?Go to Step 5Go to Step 4
4Inspect the stabilizer shaft link for wear or damage. Repair if necessary. Did you find and correct the condition?Go to Step 6Go to Step 2
5Replace the springs as necessary. Did you complete the repair?Go to Step 6
6Drive the vehicle in order to verify the repair. Did you correct the condition?System OKGo to Step 3

Suspension Bottoms

StepActionYesNo
DEFINITION: A loud bang or thump that can usually be felt and/or heard when the vehicle is driven over bumps. This condition is commonly noticed when the vehicle trim height is too low.
1Did you review the General Description and perform the necessary inspections?Go to Step 2Go to SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS
2Verify that the suspension bottoms. Does the vehicle operate normally?System OKGo to Step 3
3Inspect for vehicle overloading and correct the overloading condition as necessary. Refer to VEHICLE CERTIFICATION, TIRE PLACARD, ANTI-THEFT, AND SERVICE PARTS ID LABEL for specifications. Did you find and correct the condition?Go to Step 6Go to Step 4
4Inspect the following components: Inspect the shock absorbers. Refer to SUSPENSION STRUT AND SHOCK ABSORBER TESTING - ON VEHICLE Inspect for damaged coil springs, torsion bar or leaf springs and replace as necessary. Did you find and correct the condition?Go to Step 6Go to Step 5
5Inspect the vehicle trim height. Refer to TRIM HEIGHT INSPECTION . Did you complete the trim height inspection procedure?Go to Step 6
6Drive the vehicle in order to verify the repair. Did you correct the condition?System OKGo to Step 3

Memory Steer

StepActionYesNo
DEFINITION: A lead or pull in the direction the driver previously turned the vehicle. Additionally, after turning in the opposite direction, the vehicle will want to lead or pull in that direction.
1Did you review the General Description and perform the necessary inspections?Go to Step 2Go to SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS
2Verify that memory steer is present. Does the system operate normally?System OKGo to Step 3
3Raise and support the vehicle. Refer to LIFTING AND JACKING THE VEHICLE . Lubricate the tie rod ends and the ball joints if applicable. Inspect the suspension system for worn or damaged components. Repair if necessary. Did you find and correct the condition?Go to Step 7Go to Step 4
4Inspect for binding strut bearings. Disconnect the strut from the steering knuckle. If the strut is abnormally difficult to rotate, repair or replace the upper bearing mount. Did you find and complete the repair?Go to Step 7Go to Step 5
5Inspect for binding in the lower ball joints. If joint is binding, replace the joint. Did you find and complete the repair?Go to Step 7Go to Step 6
6Inspect the wheel alignment and adjust as necessary. Refer to WHEEL ALIGNMENT MEASUREMENT . Did you complete the wheel alignment?Go to Step 7
7Operate the vehicle in order to verify the repair. Did you correct the condition?System OK
DTCDescription
DTC C0000Vehicle Speed Information Circuit Invalid Data
DTC C0575Left Front Damper Actuator Circuit
DTC C0580Right Front Damper Actuator Circuit
DTC C0585Left Rear Damper Actuator Circuit
DTC C0590
DTC C0595Left Front Acceleration Sensor Circuit
DTC C0600Right Front Acceleration Sensor Circuit
DTC C0605Left Rear Acceleration Sensor Circuit
DTC C0670Left Front Acceleration or Position Sensor Circuit
DTC C0675Right Front Acceleration or Position Sensor Circuit
DTC C0720Engine Torque Management Feedback Signal Invalid Data
DTC C0870Control Module Voltage Reference Output Circuit

ELECTRONIC CHASSIS CONTROL DTC INDEX

Electrical Information Reference

  1. «CIRCUIT TESTING»(ref-652238-S32451086822014082300000)
  2. «CONNECTOR REPAIRS»(ref-652238-S24409892572014082300000)
  3. «TESTING FOR INTERMITTENT CONDITIONS AND POOR CONNECTIONS»(ref-652238-S35849067632014082300000)
  4. «WIRING REPAIRS»(ref-652238-S13433242552014082300000)

Circuit/System Verification

Ignition ON, observe the scan tool EBCM Wheel Speed Sensor parameters. The parameters displayed should be within 1.6 km/h (1 mph) on all sensors when driving in a straight line at a speed greater than 20 km/h (13 mph).

Repair Instructions

Perform the DIAGNOSTIC REPAIR VERIFICATION after completing the diagnostic procedure.

CONTROL MODULE REFERENCES for module replacement, programming and setup.

  1. «CIRCUIT TESTING»(ref-652238-S32451086822014082300000)
  2. «CONNECTOR REPAIRS»(ref-652238-S24409892572014082300000)
  3. «TESTING FOR INTERMITTENT CONDITIONS AND POOR CONNECTIONS»(ref-652238-S35849067632014082300000)
  4. «WIRING REPAIRS»(ref-652238-S13433242552014082300000)

Ignition ON, with a scan tool, command the Damper Actuator Increase and Decrease while observing the Damper Actuator Command parameter. The parameter should vary between 0-1000 mA. Listen/feel the Q37 shock absorber actuator. The component should activate when changing between the commanded states.

Perform the DIAGNOSTIC REPAIR VERIFICATION after completing the diagnostic procedure.

  1. «STRUT, STRUT COMPONENT, OR SPRING REPLACEMENT»(ref-652269-S37185357082014082300000)
  2. «SHOCK ABSORBER REPLACEMENT»(ref-652268-S07211854622014082300000)
  3. «CONTROL MODULE REFERENCES»(ref-652232-S11179918262014082300000) for suspension control module replacement, setup, and programming
  1. «CIRCUIT TESTING»(ref-652238-S32451086822014082300000)
  2. «CONNECTOR REPAIRS»(ref-652238-S24409892572014082300000)
  3. «TESTING FOR INTERMITTENT CONDITIONS AND POOR CONNECTIONS»(ref-652238-S35849067632014082300000)
  4. «WIRING REPAIRS»(ref-652238-S13433242552014082300000)

Ignition ON, observe the scan tool Vertical Body Acceleration parameters. The parameters should be 0 m/s 2 .

Perform the DIAGNOSTIC REPAIR VERIFICATION after completing the diagnostic procedure.

  1. «ELECTRONIC SUSPENSION FRONT VERTICAL ACCELEROMETER REPLACEMENT - UPPER»(ref-652233-S07348162632014082300000)
  2. «ELECTRONIC SUSPENSION, VERTICAL ACCELEROMETER REPLACEMENT - REAR»(ref-652233-S23741771422014082300000)
  3. «CONTROL MODULE REFERENCES»(ref-652232-S11179918262014082300000) for electronic suspension control module replacement, setup, and programming
  1. «CIRCUIT TESTING»(ref-652238-S32451086822014082300000)
  2. «CONNECTOR REPAIRS»(ref-652238-S24409892572014082300000)
  3. «TESTING FOR INTERMITTENT CONDITIONS AND POOR CONNECTIONS»(ref-652238-S35849067632014082300000)
  4. «WIRING REPAIRS»(ref-652238-S13433242552014082300000)

Ignition ON, observe the scan tool Vertical Wheel Acceleration parameters. The parameters should be 0 m/s 2 when the vehicle is parked on a level surface.

Perform the DIAGNOSTIC REPAIR VERIFICATION after completing the diagnostic procedure.

  1. «ELECTRONIC SUSPENSION FRONT VERTICAL ACCELEROMETER REPLACEMENT - LOWER»(ref-652233-S42765125442014082300000)
  2. «CONTROL MODULE REFERENCES»(ref-652232-S11179918262014082300000) for suspension control module replacement, setup and programming
  1. «CIRCUIT TESTING»(ref-652238-S32451086822014082300000)
  2. «CONNECTOR REPAIRS»(ref-652238-S24409892572014082300000)
  3. «TESTING FOR INTERMITTENT CONDITIONS AND POOR CONNECTIONS»(ref-652238-S35849067632014082300000)
  4. «WIRING REPAIRS»(ref-652238-S13433242552014082300000)

Perform the DIAGNOSTIC REPAIR VERIFICATION after completing the diagnostic procedure.

CONTROL MODULE REFERENCES for control module replacement, setup and programming

  1. «CIRCUIT TESTING»(ref-652238-S32451086822014082300000)
  2. «CONNECTOR REPAIRS»(ref-652238-S24409892572014082300000)
  3. «TESTING FOR INTERMITTENT CONDITIONS AND POOR CONNECTIONS»(ref-652238-S35849067632014082300000)
  4. «WIRING REPAIRS»(ref-652238-S13433242552014082300000)

Ignition ON, observe the scan tool Suspension Position Sensor 5 V Reference parameter. The parameter should be 4.8-5.2 V.

Perform the DIAGNOSTIC REPAIR VERIFICATION after completing the repair.

  1. «ELECTRONIC SUSPENSION FRONT VERTICAL ACCELEROMETER REPLACEMENT - UPPER»(ref-652233-S07348162632014082300000)
  2. «ELECTRONIC SUSPENSION FRONT VERTICAL ACCELEROMETER REPLACEMENT - LOWER»(ref-652233-S42765125442014082300000)
  3. «ELECTRONIC SUSPENSION, VERTICAL ACCELEROMETER REPLACEMENT - REAR»(ref-652233-S23741771422014082300000)
  4. «CONTROL MODULE REFERENCES»(ref-652232-S11179918262014082300000) for suspension control module replacement, setup, and programming

Symptoms - Suspension General Diagnosis

Note. The following steps must be completed before using the symptom tables.

Review the system description and operation in order to familiarize yourself with the system functions. Refer to the appropriate description and operation

  1. «NOISE DIAGNOSIS - FRONT SUSPENSION»(ref-652233-S42924376142014082300000) for the front suspension
  2. «GENERAL DESCRIPTION»(ref-652234-S38285988032014082300000) for tires and wheels

Trim Height Measurements

Trim height is a predetermined measurement relating to vehicle ride height. Incorrect trim heights can cause bottoming out over bumps, damage to the suspension components, and symptoms similar to wheel alignment problems. Check the trim heights when diagnosing suspension concerns and before checking the wheel alignment.

Perform the following before measuring the trim heights

  1. Set the tire pressures to the pressure shown on the certification label. Refer to «VEHICLE CERTIFICATION, TIRE PLACARD, ANTI-THEFT, AND SERVICE PARTS ID LABEL»(ref-652230-S29272294722014082300000) .
  2. Check the fuel level. Add additional weight if necessary to simulate a full tank.
  3. Ensure the rear compartment is empty except for the spare tire.
  4. Ensure the vehicle is on a level surface, such as an alignment rack.
  5. Close the doors.
  6. Close the hood.
  7. All dimensions are measured vertical to the ground. Trim heights should be within 13 mm (0.5 in) to be considered correct.

Scheme 9

Scheme 9: Measuring the P and R Dimension
Scheme 9: Measuring the P and R Dimension

Use the following procedure to check the P and R dimensions

  1. Use your hands to lift the front bumper approximately 38 mm (1.59 in).
  2. Remove your hands and allow the vehicle to lower.
  3. Use your hands to jounce the front of the vehicle downward approximately 38 mm (1.59 in).
  4. Remove your hands and allow the vehicle to rise.
  5. The dimension P for the left and right side of the vehicle is measured from the bottom lip of the wheel opening to the ground, measured at the center line of the front wheel.
  6. Compare the measurement to the specification table. Refer to «TRIM HEIGHT SPECIFICATIONS»(ref-652233-S23463801352014082300000) .
  7. If the measurement is outside of the specified range, replace the front springs. Refer to «STRUT, STRUT COMPONENT, OR SPRING REPLACEMENT»(ref-652269-S37185357082014082300000) .
  8. Use your hands to lift the rear bumper approximately 38 mm (1.59 in).
  9. Remove your hands and allow the vehicle to lower.
  10. Use your hands to jounce the rear of the vehicle downward approximately 38 mm (1.59 in).
  11. The dimension R for the left and right side of the vehicle is measured from the bottom lip of the wheel opening to the ground, measured at the center line of the rear wheel.
  12. Compare the measurement to the specification table. Refer to «TRIM HEIGHT SPECIFICATIONS»(ref-652233-S23463801352014082300000) .
  13. If the measurement is outside of the specified range, replace the rear springs. Refer to «STRUT, STRUT COMPONENT, OR SPRING REPLACEMENT»(ref-652269-S37185357082014082300000) .

Z Height Measurement

The Z height dimension measurement determines the proper ride height for the front end of the vehicle. There is no adjustment procedure. Repair may require replacement of suspension components.

Scheme 10

Scheme 10: Z Height Measurement
Scheme 10: Z Height Measurement
  1. Lift the front bumper of the vehicle up about 38 mm (1.5 in).
  2. Gently remove your hands. Let the vehicle settle.
  3. Repeat this operation for a total of 3 times.
  4. Measure from the pivot bolt center line down to the lower corner of the lower ball joint in order to obtain the Z height measurement.
  5. Push the front bumper of the vehicle down about 38 mm (1.5 in).
  6. Gently remove your hands.
  7. Allow the vehicle to settle into position.
  8. Repeat the jouncing operation 2 more times for a total of 3 times.
  9. Measure the Z dimension.
  10. The true Z height dimension number is the average of the high and the low measurements. Refer to «TRIM HEIGHT SPECIFICATIONS»(ref-652233-S23463801352014082300000) .

D Height Measurement

The D height dimension measurement determines the proper rear end ride height. There is no adjustment procedure. Repair may require replacement of suspension components.

Scheme 11

Scheme 11: D Height Measurement
Scheme 11: D Height Measurement
  1. With the vehicle on a flat surface, lift upward on the rear bumper 38 mm (1.5 in).
  2. Gently remove your hands. Allow the vehicle to settle into position.
  3. Repeat the jouncing operation 2 more times for a total of 3 times.
  4. Measure the vertical distance between the center line of the inboard rear lower control arm bolt and center line of the outboard rear lower control arm bolt.
  5. Push the rear bumper downward to 38 mm (1.5 in).
  6. Gently remove your hands. Allow the vehicle to settle into position.
  7. Repeat the jouncing operation 2 more times for a total of 3 times.
  8. Measure the D height dimension.
  9. The true D height dimension number is the average of the high and the low measurements. Refer to «TRIM HEIGHT SPECIFICATIONS»(ref-652233-S23463801352014082300000) .
  10. If these measurements are out of specifications, inspect for the following conditions: Improper weight distribution Collision damage Worn or damaged suspension components

Time studies - Suspension, rear

Object code - IDDescriptionModel yearCorrectionTerminalTime (hrs)
73211-01Spring2011012.2
73212-01Spring support, lower2011014.7
73212-02Spring support, lower2011012.5
76116-01Electronic unit, CDC2011010.5
76131-01Shock absorber, rear20110103040.5
76210-01Antiroll bar, front2011010.9
76212-01Rubber bushing, clamp, front20110103041.1
76214-01Link201101050.4
76214-02Link201101020.3
76220-01Antiroll bar, rear2011010.5
76223-01Rubber bushing, clamp, rear20110103040.3
76233-01Tie bar2011010.4
76253-01Transverse link20110103040.3
76253-02Transverse link20110103042.3
76253-03Transverse link201101020.5
76263-01Steering swivel member20110103041.2
76263-02Steering swivel member20110103041.2

Correction

  1. 01 - Replacement
  2. 02 - Removal - Refit
  3. 03 - Renovate
  4. 04 - Paint
  5. 05 - Adjust
  6. 06 - Change comp. unit
  7. 07 - Lubricate - Clean - Polish
  8. 08 - Check/Fault search
  9. 09 - Expose
  10. 10 - Install new
  11. 11 - Transfer

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