hi all,
I have a 2007 TD4 and a problem with it:

1. car is not cranking
2. BC: system engine fault
3. hazard flashes when connection battery or I turn ignition on
4. no connection via obd possible

I checked all fuses and relays and tried with chancing the CJB and engine box.
well car is not cranking seems to be clear if there is a problem with the engine controller, no obd might be clear is there is a CAN error anywhere ... but the hazard light flashing? isn't it an indication for an active impact?

any new ideas?

 

You may need to find someone with SDD or a reader that will read all Jag specific codes. Many crash do not show up as OBD codes. Although it should say crash on dash screen.

 

well, finally I forgot to say, the LR2 has been at Landrover, too. they told me they couldn't reach the OBD too but shown me a failure report ... wired

 

Did they use SDD or just checked using OBD reader? Even with total CAN bus failure they should be able to reach some modules and see what is not responding. Did they give you a copy of the report?

 

If both the medium and high speed CAN buses are dead, how exactly is SDD going to be able to talk to any modules? The Local Interconnect Bus is not surfaced in the diagnostic port, only CAN BUS High Speed High and Low and CAN BUS Medium Speed High and Low, along with the data connection pins for SAE J1850 and the other one that the garden variety OBD readers use.

 

True. I should have been more specific. OBD readers usually only talk on one bus andoften through only one module. A total loss of that bus does not mean the other is dead. Often it only takes one module problem to prevent generic OBD from working but the bus is fine. I do not think there has been any bus diagnostics done on his system.

 

IMO in our case all the data to the diagnostic port comes through one place, the CJB. If there is a problem there, nothing will work when connected to the port. Follow the sparks on the schematic, I was taught.

 

hi, therefore I changed the CJB but without success. than I checked the pins/cable from the CJB to the OBD port with a multimeter, ok too.

 

The CAN is a twisted pair ring network, so if nothing comes up the only place it could die is the CJB or possibly something called the Module-Active On-Demand Coupling. I have no clue where that is.

 

I do not believe that is correct. Every module transmits on the bus it connects to. This is regardless of if a module dies. The other modules data still shows up at the OBD port and the appropriate reader will pick it up. The CJB does not pick up the data and resend it or there would be double data on the bus. If there is a break in the bus some data will be available as long as the break is not on the OBD connector stub line.