Delphi MT60 Car ECU low resistance CAN/L/H to GND

[Gjackson]

Hi all,

I have a delphi MT60 car ECU which has no communication, dashboard fails to light up and so does the car. With all other devices unplugged and the ECU on my bench I powered it and tested the CAN lines, 2.5v solid on each with no activity seen on my scope. Resistance between CAN lines and ground Is 18k for both which is unusuall, I found some sources stating to reball a gate array IC found inside the ECU which I did but resistance didn't change.

Any ideas? Thanks

[Gjackson]

Re: Delphi MT60 Car ECU low resistance CAN/L/H to GND

short update:

I measured CAN to sensor GND and not body GND, could this be the reason why the resistance reads low? Also should I expect to see activity on CAN high/low with nothing else plugged into the ECU?

[stj]

Re: Delphi MT60 Car ECU low resistance CAN/L/H to GND

forget the canbus, establish if it's dead by looking at the cpu for activity on it's lines

[Gjackson]

Re: Delphi MT60 Car ECU low resistance CAN/L/H to GND

I couldn't find any information about any ICs onboard. I've included a picture of the PCB, tried searching up the CPU but could only find a similiar tricore model by infineon which I think has differing pinouts

datasheet: https://cdn.badcaps-static.com/pdfs/...5aac51b2ee.pdf

The top left IC is the BGA gate array that I reflowed, the top right IC is a voltage regulator which I could find no information regarding pinouts again. and bottom right is some engine idle sensor.

Most interesting of course are the top 3 chips, first step would be to make sure that CPU has core voltage but that's difficult to do without proper datasheets and I suspect it's present by the fact that both the CPU and Gate array heat up under my thermal camera to expected levels. How would I go about scoping the I/O pins for "normal" behaviour?

Thanks again!

[stj]

Re: Delphi MT60 Car ECU low resistance CAN/L/H to GND

just run a scope around it to see if it has pulsing lines anywhere and that the crystal is running

[CapLeaker]

Re: Delphi MT60 Car ECU low resistance CAN/L/H to GND

If you want the can bus to come on on any module, you have to terminate it in order that it knows it’s on a network, or run the module in the can bus network. If that crystal isn’t going, nothing else will work either. You need to get the car and do your own diagnostics and not just get handed along a ecu with hear say saying: fix it!

[Gjackson]

Re: Delphi MT60 Car ECU low resistance CAN/L/H to GND

Good point!

ECU's are especially difficult to diagnose without the actual vehicle, regarding the CAN bus I did terminate it with a 120ohm resistor at both ends but still saw no data being transmitted, probably because the ECU requires inputs to react. I'll check the crystal when I have time.

Thank you.