(Vauxhall Astra and Mercedes Sprinter)
The cruise control consists of three basic components :-
1) The Actuator. This is a stepper motor driven unit that operates the accelerator system with a flexible (bowden) cable in exactly the same manner as the drivers accelerator pedal does. It mounts in the engine compartment and is fitted with one multipole connector. It connects mechanically alongside the normal throttle cable.
2) The control unit. This is a small black box that you mount under the dash. It is the “brains” for the cruise control system and includes a small computer, a diagnostic LED, a row of 10 small switches and a wiring harness with plugs and terminals.
3) The command module. This is the bit the driver plays with!. Several shapes are available but all have the same basic controls. The simplest has three buttons. One marked SET/ACC, one marked RES/DEC and one marked COAST. It is important that you mount your command module where it is easily accessible without taking your hands off the steering wheel. The command module is fitted with a harness and multipole connector.
4) It is just possible that you may need to use a sensor coil and some magnets. These are supplied as part of the basic kit just in case.
The cruise control needs some signal to tell it the speed of the vehicle. On manual vehicles the speed of the engine will do. On automatics most vehicles today have an impulse counting speedometer. Most diesels have a tachometer and this is invariably driven from impulses from a third terminal on the vehicles alternator. If your car is an old petrol banger then it will have a coil and a set of points. Any of these pulse sources are suitable for use by the ES001 cruise control. If you have none of these then the kit includes some special wire clips and magnets and a pick up coil. The magnets are fitted to a drive shaft and the pick up coil is mounted reasonably close - like within 25 mm or so with brackets supplied. It is not that fussy.
The kit was very comprehensive with half a professional Mecano kit thrown in to enable each bit to be fitted one way or other in almost every application. The instructions were equally comprehensive. Those with an engineering background will always find more elegant ways of mounting the bits than possible with the Mecano! The electrical part of the installation is straight forward if you READ THE INSTRUCTIONS. The kit includes a pile of ScotchLocks and the harness from the control unit includes two multipole connectors to mate with those from the Actuator and Command module. Other connections include 12 volts from the key switch, negative (chassis), each side of the foot brake switch. (it won’t work if these are not both connected) and a pulse input from somewhere.
THE CRUISE CONTROL IN USE
Drive the car normally at the speed you wish to maintain and press the SET/ACC button and release your foot from the accelerator. The ES001 WILL control the throttle for you to maintain that speed. If you want to increase speed then tap the SET/ACC button a few times, about 2 taps = + 1MPH. If you want to slow down a bit tap the DEC/RES button. One touch of the brake pedal or the COAST button immediately releases accelerator control back to the drivers pedal. If you want to resume the speed last set having cancelled for some reason then touch the DEC/RES button, the car will smoothly accelerate up to then maintain the last set speed. This resume feature does not work if the key switch has been turned off.
Notes for fitting a cruise control on an old Vauxhall Astra This vehicle was a diesel with a mechanical fuel pump. no electronics!
ACTUATOR This was mounted to the bulk head with a locally made bent plate and is off centre towards the near side of the vehicle, . Two holes were drilled into the bulk head after the plastic pollen filter cover was removed to provide access. This cover was replaced afterwards. The vehicles existing accelerator cable sheath abutment was removed and an additional plate welded to it to enable the cruise control cable sheath to be fixed alongside the pedal cable.
DIESEL PUMP The existing actuator has a plastic identifying label which was removed to reveal a 5mm hole in the actuating arm. An additional arm was fashioned from 20X20X3mm angle and formed to rise over the existing pedal cable end and provide a fixing for the cruise cable inner, outboard of the manual cable. Most of the angle was cut away from this shaped new actuator but sufficient angle remained to run alongside the original actuator so that when fixed with a single 5mm bolt and nylock nut was securely located and fixed. A small amount of the plastic fan cowling was filed away to ensure that the cruise cable had sufficient clearance to allow for engine movement.
The cruise control cable followed a smooth natural curve and was secured by cable ties where it naturally positioned itself.
PULSE PICK UP Although this van does not have a tachometer the alternator and engine compartment wiring was provisioned for one as it is fitted in the car and estate versions of the vehicle. The Alternator has one thick cable to battery positive. Two other small wires leave the alternator and join to the vehicles harness with a 2 way connector which is fixed above the cam box near the bulkhead at the drivers side. Wire colours are GREEN/WHITE To Ign warning light and GREEN/BROWN to tacho. An oscilloscope confirmed that rectangular pulses of 15 volt amplitude and with frequency varying with speed were on the GREEN/BROWN wire. The inner of the cruise control coax was connected with Scotchlock to the green/brown wire. The Screen was insulated and secured safely.
Harness connections herewith:-.
Coax Inner BLUE Sensor coil or pulse input.
Coax Screen BLACK coil neg. (Cut back & insulated on Astra)
ORANGE Fused battery positive via key switch.
GREEN Chassis negative
BROWN Foot brake switch terminal 1.
BROWN/WHITE Foot brake switch terminal 2
YELLOW Ignition coil neg (points) if manual petrol. (Not used on Astra)
VIOLET Inhibit. (Ground to inhibit) (Not used on Astra)
4 core Green, Blue, Pink, Black to stepper motor / actuator.
(Fill connector with silicon grease to keep out the water.)
4 core to command module Green, Yellow, Red & Brown.
(Take care with ribbon on sharp edges under dash.)
BIT SWITCH SETTINGS that provided good smooth control in 5th & 4th a small overshoot in third and lumpy control in second gear down to 15 MPH were :- (1=on. 0=off). In first gear the overshoot was such that the cruise control would disengage.
1 2 3 4 5 6 7 8 9 10
1 1 1 0 1 0 0 0 0 0
With these settings and without a clutch switch fitted the engine revs would only increase slightly before the control disengaged when the clutch was depressed whilst cruising.
All the functions of the bit switch are detailed below.
2000 5000 8000 11300 20000 32000 45200 80000 128000 180300
1 1 0 0 1 0 0 1 0 0 1
2 0 0 1 1 0 1 1 0 1 1
3 0 0 0 0 1 1 0 1 1 1
4 0 0 0 0 0 0 0 1 1 1
5 GAIN 0 = low 1 = med 0 = high 1 = very high
6 GAIN 0 = low 0 = med 1 = high 1 = very high
7 INITIAL PULL IN 0 = low 1 = med 0 = high 1 = very high
8 INITIAL PULL IN 0 = low 0 = med 1 = high 1 = very high
9 SENSOR SELECT 0 Magnet 1 Tacho
10 SENSOR SELECT 0 Magnet 1 TachoMORE NOTES FOR A 1997 MERCEDES SPRINTER INSTALLATION.
This vehicle is "fly by wire" with the accelerator connected to a potentiometer by a short Bowden cable.
The cruise control microprocessor control module was mounted above the passengers foot well just to the side of a large plastic lined hole the other side of which was the accelerator potentiometer. This hole was used to run wiring into the engine compartment. The module was attached to the main wiring harness with a couple of stout cable ties. Its important that this module is not in "line of fire" from the heater outlets!
I mounted the stepper motor actuator unit on a sub plate which was held to the vehicle by the wiper motor securing bolts. I changed these bolts to longer ones to ensure the same length of thread engagement. The jaunty angle of the actuator mounting position was to maximise the bend radius of the control Bowden cable. Having made very comprehensive sketches I removed the accelerator potentiometer and its actuating bracket. Taking great care the actuating arm was removed from the accelerator and extended to enable the new Bowden cable to be fitted. Another bracket was fitted to the potentiometer mounting bracket to take the outer of the Bowden cable. The parts were assembled and re-fitted back into the vehicle.. I considered using one of two standard command modules but quickly decided that the joy stick method used previously on the Astra was more ergonomic. The electrics did find a few surprises! The main vehicle fuse box is beneath the steering wheel under a plastic cover. This cover is easily removed and so is the fuse box complete when you spot the fixing screws. It is very important when re-fitting this fuse box that these screws are fully wound back in. If they are not fully screwed in electrical circuits are not all made; my problem was no horn! However using a test meter (or test lamp) a 12-volt supply, which is controlled by the key switch, was identified and tapped into via the ES001 in line fused ORANGE wire. A stud under the dash on the passenger’s side provided a chassis connection to which the ES001 GREEN wire was coupled.
The Sprinter 312 sports an engine rev counter so I expected a pulse output from the alternator that I could use as a speed signal for the cruise control. Having undone the fixings to remove the bottom cover from below the Merc’s engine bay to access the alternator the pulse output connection was found, however there were no wires connected to it whatsoever. This terminal tab now is uniquely connected to the cruise control via the middle blue wire of the co-axial screened cable. Great care was taken to route this wire well clear of hot bits like the exhaust manifold.
I never found how the tacho operated but there must be some other sensor on the engine for its management system, which presumably drives the tacho as well.
The electrical connections to the brake pedal switch were straightforward when you hang upside down and look under the dash you can see the two connections to the switch where the cruise control BROWN and BROWN/WHITE wires were fastened.
The bit switch settings started as I had optimised for the Vauxhall Astra but were later altered very slightly to increase the gain of the system to reduce speed droop on hills. Bit switch settings ended up thus:-
1 2 3 4 5 6 7 8 9 10
1 1 1 0 0 1 0 0 0 0
We could have set the system to maximum gain but this caused the system to hunt in third gear. Its very useful being able to trickle slowly through sleepy French Villages in the early morning using the cruise control when looking for a Boulangerie to buy ones breakfast.
One warning if you are contemplating fitting this cruse control yourself, My installation showed that the full stroke of the cruise control actuator was JUST enough to operate the accelerator fully. If I were doing it again I would mount the fixing for the Bowden cable inner a little closer to the existing fixing for the manual accelerator cable to reduce the Bowden cable travel.
CIRCUIT DIAGRAM OF COMMAND MODULE
Pictures down the page OK!
VARIOUS STANDARD COMMAND MODULES
ACTUATOR MOUNTING PLATE
ACCELERATOR POTENTIOMETER FIXING BRACKETS
HOME MADE JOYSTICK IN BOX
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