Active Cornering Enhancement (ACE) - Lamp ON
No: 60/05/03/NASRef:
Issue: 1
Date: 04/25/03
ACE Warning Lamp Illumination
AFFECTED VEHICLE RANGE:
Discovery Series II (LT) Up to 3A805135 Equipped with ACE
SITUATION:
AMBER LAMP ILLUMINATES ON LEVEL SURFACE
The customer may complain that after driving in a straight line and on a level surface for a continuous period of fifteen minutes, the amber Active Cornering Enhancement (ACE) warning light illuminates.
The cause may be on of the following conditions:
^ The upper accelerometer calibration has not been stored in the ACE Electronic Control Unit (ECU)
^ The upper accelerometer mounting bracket is deformed
^ The upper accelerometer has a fault.
RESOLUTION:
CALIBRATE OR REPLACE UPPER ACCELEROMETER
When the symptoms of the above complaint are confirmed, perform the troubleshooting procedures in this TIB and if indicated replace the upper accelerometer.
PARTS INFORMATION:
RQJ100010 Accelerometer Qty 1
WARRANTY CLAIMS:
REPAIR 1
60.90.06 Time 0.20 Hours
Upper Accelerometer Testbook/T4 diagnosis - includes calibration
FAULT CODE: A
REPAIR 2
60.60.89/35 Time 0.40 Hours
Upper Accelerometer Testbook/T4 diagnosis and re-align - includes calibration
FAULT CODE: A
REPAIR 3
60.60.89/35 Time 0.40 Hours
Upper Accelerometer Testbook/T4 diagnosis and replacement - includes calibration
FAULT CODE: U
Normal warranty policy and procedures apply.
Material allowance is included in labor operation.
REPAIR PROCEDURE
REPAIR 1: TESTBOOK DIAGNOSIS
1. Position vehicle on a level surface and ensure that the air suspension is active.
2. Connect TestBook/T4 to the vehicle through an open window and load disc DRG0018 or a later version.
3. Verify no other repair work is being carried out to the vehicle when using TestBook/T4.
4. Follow the on-screen instructions and select "Diagnostic System".
5. Follow the on-screen instructions and select "ACE"
6. Follow the on-screen instructions and select "Fault Code Diagnostics".
NOTE:
If any of the fault codes stored are other than "Upper Lateral Accelerometer out of range", TestBook/T4 must be used to diagnose and repair the fault. Faults not relating to the upper lateral accelerometer out of range are not part of this repair process. Repairs for these unrelated faults are to be carried out as a separately before continuing with this bulletin.
7. If any of the fault codes stored are not "Upper Lateral Accelerometer out of range", use TestBook/T4 to diagnose and repair the fault.
8. If fault code "Upper Lateral Accelerometer out of range" is stored, or there are no fault codes stored, then continue from the next step to obtain a real-time display output value for the upper accelerometer.
NOTE:
Record the real-time display output values for the upper and lower accelerometer that TestBook/T4 displays and any ACE fault codes stored in the ECU on the job card.
9. Follow the on-screen instructions and select "Real-Time Display".
10. Not provided by O.E.
11. Follow the on-screen instructions and select Lateral Accelerometers and record real time values.
12. If the Upper Accelerometer output on TestBook/T4 is within the range (-0.05G to +0.05G) the fault is not with the upper accelerometer installation. Investigate further and claim separately.
13. If the Upper Accelerometer output on TestBook/T4 is between -0.05G and -0.17G or between +0.05G and +0.17G go to "CALIBRATION" section.
REPAIR 2: CHECK ACCELEROMETER ALIGNMENT
1. If the Upper Accelerometer output on TestBook/T4 is outside of the range -0.17G to +0.17G, refer to RAVE section 76.67.26 and remove front stowage pocket.
2. Check alignment of accelerometer retaining bracket.
3. If bracket is bent, re-align to return accelerometer to a horizontal plane. (Figure 1).
REPAIR 3: REPLACE ACCELEROMETER
1. If the Upper Accelerometer output on TestBook/T4 is outside of the range -0.17G to +0.17G, and if the accelerometer's retaining bracket is NOT bent, refer to RAVE section 60.60.02 and replace the accelerometer.
CALIBRATION
1. When diagnosis, alignment or replacement repairs are concluded, perform the TestBook/T4 calibration process as follows:
^ Follow the on-screen instructions and select "Diagnostic System".
^ Follow the on-screen instructions, select "Fault Code Diagnostics" and clear all faults found from the ACE system ECU.
^ Follow the on-screen instructions and select "Vehicle Maintenance".
^ Follow the on-screen instructions and select "Calibrate Accelerometers".
^ Calibrate Accelerometers.
^ Follow the on-screen instructions and select "Real Time Display".
^ Follow the on-screen instructions and select "Lateral Accelerometers".
^ Confirm that the real time display values are within -0.05G to +0.05G.
2. Return to the Diagnostic System screen and disconnect TestBook/T4 from the vehicle.
3. Refer to RAVE section 76.67.26 and install the front stowage pocket.