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Disco w

D2 clutch switch circuit diagram

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Hi I have a 2001 Disco 2 td5. My cruise control is not working I have checked with a Nanocom and it shows the clutch switch permanently depressed.

I have checked the clutch switch operation and it is OK but there is no voltage on either terminal of the connector block for it.

Does anyone know of a circuit diagram for the clutch switch.

One I have found for a later disco suggests that the brake switch and the clutch switch are connected in series and to a terminal on the ECU. will this be the same for mine.

Other sites have differing opinions on connections and voltages which range from 5 volts to 12 volts.

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Nanocom should show the live switch inputs and show the change when the pedal is depressed.

I believe the circuit needs to be closed for CC to work, so try removing the connectors from the switch on the clutch master cylinder and short between the two connectors and go for a drive.

Does Nanocom show your brake switch changing state when you depress the pedal? (Do your brake lights work !!)

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Hi thanks I have tried all this and it did not work that is why I got a multi meter out to check if there was any voltage to either side of the switch and there is none.

I have traced the cable from the clutch switch to the ECU and that cable is OK.

Unable to trace or find information on the other cable which possibly goes the the brake switch normally closed closed contact but the two wires are different colours and there does not appear to be a connection between them.

My Nanocom shows both switches on the brake pedal are operating when I push the brake pedal.

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The clutch switch closes to earth, it's a contradiction between the description of it and the diagram but the diagram is correct and the description is not, i verified

 

clutch switch diagram.jpg

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Thank you for that I will check that out hopefully tomorrow 

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Hi I checked this morning and the one side of the clutch switch when checked with a multi-meter show a circuit to earth which agrees with your diagram.

I then connected a nanocom which shows the clutch switch on, while this was connected I removed the connection socket from the clutch switch but it still shows clutch switch on. Also tried shorting out the connections in the plug and the clutch switch was still showing on.

I seem to remember reading online a while back that some tuners may over-ride this function in the ECU. While I have no idea if my engine has been chipped do you know if this is possibly the cause.

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Hi I checked this morning and the one side of the clutch switch when checked with a multi-meter show a circuit to earth which agrees with your diagram.

I then connected a nanocom which shows the clutch switch on, while this was connected I removed the connection socket from the clutch switch but it still shows clutch switch on. Also tried shorting out the connections in the plug and the clutch switch was still showing on.

I seem to remember reading online a while back that some tuners may over-ride this function in the ECU. While I have no idea if my engine has been chipped do you know if this is possibly the cause.

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1 hour ago, Disco w said:

I seem to remember reading online a while back that some tuners may over-ride this function in the ECU. While I have no idea if my engine has been chipped do you know if this is possibly the cause.

I dont see much logic in overriding that input unless there is a auto ECU fitted to the manual vehicle. Might be a short to earth somewhere on the circuit between the Switch and ECU.

 What's the p/n on your ECU, it should be MSB101330 if it's original

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Hi I have checked the circuit between the ECU and the clutch switch and there is no earth fault.

Got brave and took the top off the ECU and was alarmed to see the strap between the pcb and the connection plug had been cut. Have checked the wiring diagrams and it seems the (light green and grey connection 34) cable is a connection between the BCU and the ECU for an automatic box( which mine is not )  so I dont think that is the problem.

Regarding your other question about a number on the ECU I can only find 1 label it has Rover, a bar code and the number *0540101193* on it.

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33 minutes ago, Disco w said:

Have checked the wiring diagrams and it seems the (light green and grey connection 34) cable is a connection between the BCU and the ECU for an automatic box( which mine is not ) 

It's certain that your ECU is something bodged cos that connection to pin 34 LGS wire is not for automatic gearbox but the security code input for all ECUs and it's a method to override the immobiliser used by ''brute" mechanics who are changing an ECU and dont have the  proper diagnostic tool to make it learn the security code, the fact that the label with the part number is missing as well makes that ECU very suspect so IMO get hold of a proper ECU which was not "invaded" cos that's your problem

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Thank you for all your help I will look for another ECU. 

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If you change the ECU I beleive that you need to change the BCU as well to avoid conflicts.If it helps I have the BCU ECU and a key from my 2000 ES but it didn't have cruise on it so you would neet to activite it with the Nanocom.

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If tester is availablle no need for BCU if the ECU is changed, it only has to learn the securirty code

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No problem. I know I changed both.

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