Cruise Control - 'Set/Hold' Inoperative

1/03/96

19/02/96/US

SUBJECT:
Cruise Control Actuator-Intermittent Operation

MODEL:
Range Rover 4.0/4.6
Range Rover Classic
Discovery
Discovery

AFFECTED VEHICLES:
LP 318333 to 320759
LH 662357 to 662708
LJ 167348 to 171917
LJ 502908 to 540244

DETAIL

A small number of vehicles within the above VIN range suffer an "Air leak" on the cruise control actuator between the actuator body and the rubber diaphragm. During "set" of the cruise control, if the actuator has an air leak, the time taken to "set/hold" the cruise speed, will be increased. In certain cases the leak may be too large, and the actuator (cruise control) will not function correctly.

ACTION REQUIRED

Upon customer complaint of a cruise control "set/hold" inoperative and a longer than normal time to achieve "set/hold", carry out the checks detailed below.

PARTS INFORMATION

ETC7150 - Cruise control actuator (Qty. 1)

PROCEDURE

Refer to the Workshop Manual section 19 Actuator

Procedure for checking the cruise control actuator.

1. Open the hood and locate the cruise control actuator unit.





2. Remove the vacuum hose from the base of the actuator "A" (see illustration).

3. Compress the diaphragm by approximately 0.1969 -0.3937 in. (5-10 mm), place finger firmly over the pipe on the actuator body to achieve a seal.

NOTE:
If the diaphragm is compressed completely the actuator may not show signs of a leak.

4. Release the diaphragm, with the hose sealed the diaphragm should remain in its depressed condition.

5. If the diaphragm returns to its normal shape repeat the test once more to confirm result.

6. If a leak is confirmed, replace the actuator.

WARRANTY:

Normal warranty policy and procedures apply

COMP.CODE:

2W3N

SRO:

19.75.12 - Cruise control actuator check/renew 0.20 hr.