NO crank from key and no comms several controllers

Andre Engineer Australia Posted   Latest   Edited  
2008 Jaguar X-Type Luxury 3.0L (AJ-V6) 5-spd (JF506E)
Non Start
Fault Code U1900

Non start, no crank from key. No comms with Engine, Transmission, Abs, tyre pressure monitor, climate conrol, drivers seat, intrusion sensor, parking aid, headlamp leveling & voice activation modules.

Vehicle did have comms until locksmith checked vehicle because of no crank and security fault flashing on screen.

Voltage at transmission can H and can L is 1.6v not sure if this correct for this vehicle.

I have checked earths and voltages to engine & transmission modules and are correct.

Any help will be greatly appreciated. 

Joel Diagnostician
Joel Default

You are dealing with a hi tech vehicle, you should have 60 ohms between pin 6 and 14 If this vehicle does not have gate way sover vehicles with gate way will not show the resitance if that leg to dlc are can foe diagnostic only, 2.5 volts on can H ycan l . You need the topologi of the wiring dIngram and topology of the network

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Jamie Owner/Technician
Jamie Default

Check resistance between Pins 6 and 14. As previously stated resistance must be close to 60 Ohms, I'm sure that you will find that it isn't. Find a wiring diagram to see what modules are on the bus and start disconnecting one by one until communication returns. It sounds to me that one is shorted stopping communication.

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Andre Engineer
Andre Default

Hi and thank you Joel & Jamie for assistance. I have sorted prolem with communication relay was removed, suspect by locksmith.

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