Control Switch and Operating Limitations & Consumer Operating Instructions
FIGURE 1:
CONTROL SWITCH AND OPERATING LIMITATIONS
The cruise switch functions must be fully understood when troubleshooting the cruise system. If the cruise is inadvertently turned off it must be turned back on first before attempting to set. The SET button must be pressed only momentarily to prevent the Cruise Module from thinking DECEL is desired. It is recommended that you become familiar with control switch functions. See FIGURE 1.
Please be aware that the safety features built into the cruise system will automatically disengage the cruise if the following operations or conditions are met:
1. The brake lamp fuse or cruise fuse blows.
2. The control switch "OFF" button is pushed (DL) or the main dash switch is turned off GL.
3. The ignition switch is turned to "ACC" or "OFF".
4. The brake pedal is depressed.
5. The clutch pedal in manual transmission vehicles is depressed.
6. The automatic transmission shift lever is placed into "P" or "N".
7. The engine speed exceeds 5000 RPM.
8. The brake light bulbs burn out.
9. The vehicle speed (speed sensor signal) varies more than + 10 mph/sec.
10. The vehicle speed drops below 25 mph.
The electronic computer that is the heart of the Subaru Cruise Control System monitors the speed of the vehicle as fast as 20 times per second and will attempt to correct speed errors of as little as 1/4 mile per hour. However, in the interest of smoothness, the unit is prevented from making throttle corrections that are too large or abrupt.
The actual performance of the cruise control system will vary from car to car depending mainly on the weight, horsepower, and specifications of the particular vehicle. Standard shift cars take advantage of engine braking and may react to road conditions differently than automatic transmission equipped vehicles. (5 speeds however, will perform similarly to automatics when in 5th gear.) On automatic transmission cars it is common for the system to have the throttle "on the floor" going up a hill and still be under the set speed, and then after cresting the hill, drop the throttle back to full idle but still roll past the set speed by several miles per hour.
The Electronic Module is non-serviceable and must be replaced if it fails. It should never be opened or altered in any way and the warranty on this item is void if the seal(s) are broken. Electronic Modules should only be suspected of failure when a thorough system check reveals component parts operating correctly.
Servo bead chains on DL and GL SW/SDN/3DR should have a small amount of slack for proper operation. Small adjustments may be accomplished by loosening the servo mounting bolts and shifting the servo. When larger amounts of adjustment are necessary, the clip may be removed from the end of the servo spacer tube and the bead chain moved in or out to give proper adjustment. In most cases the bead chain will be very close to proper adjustment out of the box.
CONSUMER OPERATING INSTRUCTIONS
Before any attempt at a repair is made, the vehicle should be test driven to determine if in fact the cruise control is inoperable and that the driving conditions are not beyond the design characteristics of the system. Another point to confirm is that the owner has read and fully understands the operating instructions for the cruise control. These operating instructions are included with every cruise kit and are to be left in the vehicle upon completion of installation. The operating instructions for the 1987 kits are reprinted below.
When the ignition key is shut off the cruise control is also shut off and must be turned back on again, DL - must push "ON" and "SET", GL - just push "SET" ( main power SW would stay depressed), after the key is switched on before cruise control can be engaged.