Campaign - Cruise Control Surge Correction
No: H108Ref: 19/01/02/NAS
*Issue: 2
Date: 02/07/03*
SERVICE ACTION
Cruise Control Surge Correction
AFFECTED VEHICLE RANGE:
Discovery Series II (LT) 3A767790 to 3A780592 (Option 1)
* 3A780593 to 3A805756 (Option 2)*
Updated information is shown by asterisks.
NOTE:
This Service action applies to vehicles in Retailer inventory. Some vehicles may have been inspected at port of entry. The port-adjusted vehicles should have a label installed and will have the campaign closed on the AS400.
Customer vehicles should be repaired upon owner complaint following the procedures and Warranty information contained in TIB 19/01/02/NAS.
SITUATION:
CRUISE CONTROL SURGE
Early 2003 Model Year production of 4.6 liter equipped Discovery Series II vehicles have a cruise control software configuration which can result in objectionable "surge" of up to 2-3 mph around the "target" speed. Additionally, an incorrectly adjusted cruise control cable or minor vacuum leaks can contribute to the sensation of "surge" even if target speed is maintained.
RESOLUTION:
VERIFY CABLE SETTING AND INSTALL NEW CRUISE CONTROL CONFIGURATION
Prior to sale verify that the cruise control cable is set correctly and investigate the current state of the cruise control tune. If necessary, update the cruise tune following the instructions in this Service Action. Installation of the updated cruise control configuration using TestBook/T4 will likely resolve the surge situation in combination with a properly set cable. If the problem persists once the new tune is installed investigate and correct any vacuum system leaks.
PARTS INFORMATION:
Not applicable
WARRANTY CLAIMS:
H108 Option 1 Time 0.40 hrs.
Check cable, evaluate cruise control configuration and update if required
H108 Option 2 Time 0.10 hrs.
Check cable and adjust cable if required
Normal warranty policy and procedures apply. Material allowance is included in labor operation.
REPAIR PROCEDURE
ADJUST THROTTLE CABLE (OPTIONS 1 AND 2)
NOTE:
The Workshop Manual provides a range for cruise throttle adjustment. The middle of that range is the optimum setting and should always be set for the best possible operation of the Cruise Control system.
1. Refer to the RAVE Workshop Manual section 19.75.11 and verify that cruise throttle cable is set with maximum 1 mm (0.040 in) gap between the cam and the lever.
VERIFY CORRECT TUNE (OPTION 1)
2. Connect TestBook/T4 to the vehicle.
3. Insert Testbook/T4 disc V016 or later.
4. Connect Blue diagnostic lead to the vehicle.
5. Turn ignition to position "II".
CAUTION:
Hand brake should be set and the transmission placed in the neutral "N" position.
6. Verify hand brake is set and transmission is in neutral.
7. Depress instrument cluster cruise master switch to place in "on" (switch illuminated) condition.
8. Select "Diagnostic System" on TestBook/T4 screen.
9. Select "Discovery, 2003MY"on the TestBook/T4 screen.
10. Enter the vehicle VIN and press "Continue" on the TestBook/T4 screen.
11. Confirm vehicle info and press "Continue" on the TestBook/T4 screen.
12. Select "Cruise Control/Petrol/Vehicle Maintenance/View Tune" on the TestBook/T4 screen.
NOTE:
At this point, Testbook will read the tune values from the vehicle and provide a display of those values.
13. Compare the tune values to the values listed below:
INSTALL UPDATED TUNE
1. If the vehicle contains different tune values than those listed in the table, select "Cruise Control/ Petrol / Vehicle Maintenance / Program ECU / Set new tune 4.6L engine" on the TestBook/T4 screen.
NOTE:
Download of the tune values from TestBook/T4 to the vehicle will take only a few seconds.
2. When programming is completed read back the tune values and verify that they match the listing in the table above.
NOTE:
The Cruise Control ECU requires some adaption time after programming. The test drive should be approximately 20 miles with cruise engaged whenever possible.
3. Test-drive the vehicle and verify that the new tune has resolved the issue of cruise surge.
VACUUM SYSTEM LEAK CORRECTION
1. If the surge persists after the test drive, investigate to determine if there are any leaks in the vacuum system and correct.
2. Test-drive the vehicle and verify that cruise surge has been corrected.
INSTALL CAMPAIGN LABEL
NOTE:
Campaign labels may have multiple Campaign numbers written on them if multiple campaigns are performed at the same time.
1. When all specified repairs have been accomplished, prepare the campaign label (LRN0002LABEL) as follows:
a) Place the label on a hard surface.
b) Use a ballpoint pen to neatly write/scribe in the bare aluminum areas of the label the following information:
^ Campaign code "H108"
^ Your retailer code
^ The date of repair.
2. Clean all grease and dirt from the radiator support member.
3. Peel the completed campaign label from the backing paper and position it on the cleaned area.
4. Roll the label with the special roller tool to ensure proper adhesion.