My scanner will not communicate on the serial k line. It does read on the the other networks. The wiring diagrams show ecu, accm, Ktm, and damper control. I do not have a Ktm or damper control. I read -11.53 v on pin 7 to ground. If I disconnect ecu I get -10.02v. With accm disconnected -11.31v. I disconnected batt. Pin 7 to gnd 39 ohms. Accm disconnected ecu to gnd 50 ohms. Ecu disconnected accm to gnd reads 193 ohms. Since ecu and accm are in parallel the resistance checks out. I tested the cable and no ground faults. I looked at both ecu and accm modules did not see any issues with traces or caps. Any ideas on why I am not getting comes?

 

Bad OBD tool, most likely.

 

Tested the scanner on another car and it worked fine.

 

Jaguars are fussy about scantools as you'll see from this thread in General Tech Help:

https://www.jaguarforums.com/forum/g...-%2A%2A-33347/

Graham

 

I am able to read can and s&p networks and have used two scan tools specific girl jaguar. I should be reading about 5 volts in pin 7 not 11v.

 

Try connecting pin 15 to pin 7...this is necessary when pin 15 from the reader does not connect the required wake-up signal needed on earlier vintage Jaguar OBDII interfaces.

 

I think you have the wrong idea of the correct voltage. Typical for ISO9141 is about 10.7V I think you'll find. It is a task of the testing device to pull the pin up to batt+ via 510 ohm resistor as I recall.

 

Thank you for your sage advice! I jumpered pin 7 & 15 and I was able to read the codes. V8 ur right also the pin is around 10v then drops to 5v. Again thanks for the help.