Classic 4.2 LSE

[TCDown]

I have never been able to get the cruise control working at all since buying my 93 model 4.2. Anyone know of any common faults with this? Also how does the manual EAS system work as hitting any of the button has no effect whatsoever?

btw be prepared for loads of q's like these, I bought the car but cant afford much on repiars so its all down to me now lol

 

[joey]

With the Cruise Control Switch (X115) on, voltage from Fuse Fi8 is applied to the Cruise Control ECU (Z121), Cruise Control Lockout Relay (K110) (Except NAS Automatic), Speed Trip Module (Z164) (Except NAS Manual), Clutch Pedal Position Switch (X200) (NAS), and the Steering Wheel Cruise Switches (X266) through the WY wire, Rotary Coupler (Z104) and PB wire. The Cruise Control ECU (Z121) is grounded at terminal 8 through the B wire to E200.

With the Ignition Switch (X134) in position II, battery voltage is applied to the Cruise Control Switch (X115) through the closed switch contacts of the Cruise Control Disable Relay (K234). The Engine Control Module (ECM) (Zi32) applies ground to the coil of the Cruise Control Disable Relay (K234) if an engine fault is detected. The relay energises, opening the switch contacts. The battery supply to the Cruise Control Switch (X115) is interrupted, disabling the Cruise Control System.

With the Cruise Control Switch (X115) on, voltage from Fuse Fi8 is applied to the Cruise Control ECU (Z121), Cruise Control Lockout Relay (K110) (Automatic), Speed Trip Module (Z164) (Manual), and the Steering Wheel Cruise Switches (X266) through the WY wire, Rotary Coupler (Z104) and PB wire. The Cruise Control ECU (Z121) is grounded at terminal 8 through the B wire to E200.

With the Cruise Control Switch (X115) on, voltage is applied to the Cruise Control Vacuum Pump (M103) through the WY wire. When a cruise speed is set, the Cruise Control ECU (Z121) applies ground through the BR wire to operate the pump motor and applies ground through the BY wire to close the normally open solenoid valve in the pump. The pump applies vacuum to the actuator.
When the RES/DECEL Switch is depressed, voltage is applied to terminal 4 of the Cruise Control ECU (Z121). This voltage signals the ECU to disengage the system, and the vehicle slows down. When the switch is depressed a second time, voltage is again applied to the ECU and the vehicle returns to the previously set speed.

To set a cruise speed, the Cruise Control Switch (X115) must be on and vehicle speed must exceed 28 mph (45 km/h) . When the SET/ACCEL Switch is depressed under these conditions, voltage from

Fuse F18 is applied to terminal 3 of the Cruise Control ECU (Z121) through the closed Cruise Control Switch (X115) and Steering Wheel Cruise Switches (X266), causing the vacuum pump to operate. When the SET/ACCEL Switch is released, voltage is removed from terminal 3, signalling the ECU to set the speed.


Terminal 11 of the Cruise Control ECU (Z121) monitors the Vehicle Speed output signal from the Instrument Cluster (Z142) through the YK wire. This signal is a pulsing voltage, and its frequency changes with vehicle speed.

The Cruise Control System can be disabled in one of four ways:
1. The Cruise Control Switch (X115) is put in the 0 position, removing power from the

 

[joey]

Cruise Control ECU (Z121) and vacuum pump and erasing the set speed memory.
2. The RES/DECEL Switch is depressed, signalling the Cruise Control ECU (Z121) to disengage the system.
3. The brake pedal is depressed, and a vacuum valve in the Brake Switch Vent Valve opens (X112). This vents vacuum to the actuator valve and releases the throttle.
4. The Voltage applied to Cruise Control ECU (Z121) terminal 9 is interrupted, causing the Cruise Control ECU (Z121) to turn off the vacuum pump and de-energise the vacuum solenoid valve. This voltage path is interrupted when the brake pedal is depressed, the Clutch Pedal is depressed, or the vehicle is in Park or Neutral. With the brake pedal depressed, the Brake Switch Vent Valve (X112) moves to 1 and the circuit is interrupted. With the vehicle in Park or Neutral, the Park/Neutral Position Switch (X167) energises the Cruise Control Lockout Relay (K110) by grounding the relay's coil. The relay then opens its contacts, interrupting the circuit. With the clutch pedal depressed, the Clutch Switch (X200) moves to 1 and the circuit is interrupted.



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Road Test


CAUTION: DO NOT ENGAGE CRUISE CONTROL WHEN VEHICLE IS BEING USED IN LOW TRANSFER GEARS

WARNING: The use of cruise control is not recommended on winding, snow covered or slippery roads, or in heavy traffic conditions where a constant speed cannot be maintained.
1. Start the engine and depress the Cruise Control Switch (X115) to activate the Cruise Control System. Accelerate to approximately 30 mph (50 km/h) and press the SET/ACCEL Switch. Immediately release the switch and remove foot from the accelerator pedal. The vehicle should maintain the speed at which the SET/ACCEL Switch was pressed.
2. Press the SET/ACCEL Switch and hold at that position. The vehicle should accelerate smoothly until the switch is released. The vehicle should now maintain the new speed at which the SET/ACCEL Switch was released.
3. Press the RES/DECEL Switch while the vehicle is in the cruise control mode. The cruise control should disengage. Slow to approximately 35 mph (55 km/h) and press the RES/DECEL Switch. Immediately release the switch and remove foot from the accelerator. The vehicle should smoothly accelerate to the previously set speed. Increase speed using the accelerator pedal. Releasing the pedal should return the vehicle to the previously set speed.
4. Depressing the brake pedal should immediately disengage the Cruise Control System and return the vehicle to driver's control at accelerator pedal. Press the RES/DECEL Switch and the vehicle should accelerate to the previously set speed without operation of the accelerator pedal.
5. Press the RES/DECEL Switch and allow the vehicle to decelerate to below 26 mph (42 km/h) . Press the RES/DECEL Switch and the Cruise Control System should remain disengaged.
6. Press the SET/ACCEL Switch below 28 mph (45 km/h) and the Cruise Control System should remain disengaged. Accelerate the vehicle above 28 mph (45 km/h) , press the RES/DECEL Switch and remove toot from the accelerator pedal. The vehicle should smoothly adjust to the previously memorized speed.
7. Pressing the Cruise Control Switch (X115) should immediately disengage the Cruise Control System and erase the previously set speed from ECU memory.

 

[joey]

How it works.
________________________________________
DESCRIPTION
The cruise control system consists of electro-mechanical devices, and comprises of the following components.

Electronic Control Unit (ECU)
The microprocessor based ECU evaluates the signals provided by the driver controls, brake pedal switch, clutch pedal switch on manual models, and the vehicle speed sensor. The ECU activates the vacuum pump as required. The ECU also has a memory function for set Speed storage.

Driver Operated Switches
The main cruise control switch is located in the auxiliary switch panel and activates the cruise control system. The steering wheel switches provide 'set/accelerate' and 'resume/decelerate' features. These switches provide the interface between driver and cruise control system.

Brake Pedal Switch
The brake pedal switch is located under the lower dash attached to the brake pedal mounting bracket. The switch provides for fast disengagement of the cruise control system and rapid return of the throttle levers to the idle position when the brake pedal is applied.

Clutch Pedal Switch
The clutch pedal switch is located under the lower dash attached to the clutch pedal mounting bracket. The switch provides for fast disengagement of the cruise control system and rapid return of the throttle levers to the idle position when the clutch pedal is applied.

Vehicle Speed Sensor
The vehicle speed sensor is located on the side of the transfer box adjacent to park brake. The sensor provides road speed data to the ECU. The cruise control system cannot be engaged until the road speed exceeds 45 km/h, (28 mph) the system will automatically disengage at a road speed of 42 km/h (26 mph).

Vacuum Pump
The vacuum pump is energized when the main cruise control switch is operated, and is actuated by the steering wheel and brake pedal switches. The pump provides a vacuum source to the cruise control actuator. A control valve in the pump provides for steady increase of road speed or purge of the system when the brake pedal is applied.

Actuator
The actuator provides the servo mechanism link between the cruise control system and throttle linkage and is operated by vacuum from the vacuum pump.

Neutral Lockout Relay - Automatic Vehicles
The relay module is located in the right hand side footwell, accessible by removing the trim casing.

The function of the relay module is to disengage the cruise control System if neutral, or park, is selected in the main gearbox, when the system is engaged.

Engine Speed Trip ECU - Manual Vehicles
This unit is located in the right hand side footwell, accessible by removing the trim casing.

The function of the unit is to disengage cruise control if engine speed exceeds 5000 rev/min

 

[TCDown]

Cheers for all of that, I will have a go at it on my way home tonight.

 

[rishi]

Could be simple. When the bonnet is open take a look in the top right hand corner. There you can find the vacuum pipe. It is a rubber pipe and mijn was leaking. I put in a new pipe for a couple of euros and now it works fine. If you need more details ask only its snowing now and I don't fancy going out and looking under the bonnet.

Regards

Rishi '95 RRC LSE