PSCAN connection to BCU

Hello, everyone.  I've got a problem with PSCAN that I'm hoping someone can help me with please.  I've messaged Philip but he's not around at the moment.  The problem is that my PSCAN interface (043C) won't connect to the Rover 75 GM6 BCU nor the EWS for the immobiliser.  Both go through the process waiting for the line to settle, slow and fast init protocols but then PSCAN fails with 'init fail' and goes back to the main screen. I can connect to the ECU with no problem but I really need to see what's in the BCU, as I'm struggling with electrical gremlins.  Can anybody help me please?  Thanks, James

Hello James
On a Rover 75 the engine ECU uses pin 7 on the diagnostic socket, and the BCU, ABS and EWS use pin 8.
My guess is that pscan can't connect to your ABS either?
There is probably a wiring fault from pin 8 of the diagnostic socket to those ECUs, or possibly one ECU is shorting the line so that nothing works.
One test that you can do with a multimeter:-

1. Test the voltage on pin 8, with nothing connected it should be 12V
2. Put you multimeter on milliamps/current (you have to plug the lead into a different position as well) and use it to short pin 8 to ground and measure the current.  It should pull a few tens of milliamps.

and then reply back with what you find.

Hi Philip.  Firstly, apologies for not replying sooner - I didn't get a notification of your reply and life's been busy the past fortnight, so sorry and thank you so much for the reply.  I've done as you suggested.  I got 8.8v from Pin 8 to ground but 0.0 from the current reading on Pin 8.  When I plugged the cables into the voltage settings but ran current, i got a reading of 0.23 on 20m.  Images attached below.  Certainly doesn't feel right to me.  The voltage showed 8.8v with the engine running or not - the battery is fully charged.  Where next please?  Thanks, James

 

 

 

This proves that pin 8 is not shorted to ground nor +12V.
Does pscan work when you select ABS5.7 ?

also, to test current on the 10A range, you have to plug the red lead into "10A max" (which you did), and you also have to twist the dial to 10.