Fiat Stilo CAN problems

[omglol]

I am getting desperate on this one. It is Stilo 1.9 JTD, 103 kW (140 hp), 1.9 JTD multijet, make year 2004.

The problem is that lots of stuff on instrument cluster aren't working: rev counter, fuel level, water temperature, oil light is always ON, triangle light, etc ... and "loose connection" message. Car also from time to time (rarely) does not want to start due to immo problem.


The Engine Control Module has these errors stored:

U1700 CAN network NCM-NBC, no signal, fatal
U1706 CAN network NCM-NFR, no signal, intermittent
U1601 C-CAN line error, no signal, intermittent


In other ECU's, there are no relevant fault codes. The Body Control Module does not have any communication related fault codes stored. The Proxy Alignment Procedure does not "see" Engine Control Module.

Here's what I did so far:

- checked wiring, looks OK. There is no D4 connector on this vehicle
- put new wires for CAN between ECM and BCM
- put used (from working car) ECM
- put used (from working car) BCM
- put used (from working car) instrument cluster
- put extra earth wire to instrument cluster, which is connected to the earth of BCM


Neither of these are doing any good. Also, I have to say that customer reported everything working OK for a while past week, then going back haywire.

Does anyone have an idea what could be wrong?!

[yellowstilo]

did you measure the resistance between pin 6 and 14 of the obd2 connector ?
should be around 60 ohm due to the two 120 ohm termination resistors parallel at both ends of the can bus.
also check the high speed can wiring the same way, it's not present on the obd connector.
also check for shorts to ground or power supply.

[omglol]

I checked the CAN bus on the power steering control module (it serves as a bridge between ECM and BCM). Resistance to ECM is 114 Ohm, to BCM is 118 Ohm. Everything OK here. Resistance between pin 14 and 6 in OBD connector is about 2 mega Ohm ... I checked on another (working) Stilo and it is also 2 meha Ohm there ...

Also, if whole CAN bus was shorted to GND or +12V there would be multiple errors on ALL control units, not just ECM.

[Tuiken]

hello here schemes of can, heart, power , dashboard if you need other tell me
imagine that when you turn the key on only ECM is feed ! the other ECU dont give error !
And the fuel meter not passes through the ECM
check the fuses box in motor and the ignition key
sorry my english

[gev]

Change can driver ecm ecu and dashboard

[Meat-Head]

Underhood fusebox full of water .

what radio dies out have?

[Stelaras]

IM FACING THE SAME PROBLEM WITH A STILLO 1.2...
Did you ever find a solution?

[volorucinski]

On my bcm was the A82c250 ic on CAN. Is near the mcu mc912.

[pizdun9245]

Did you try with ABS module?
Try unjacking it, see if some of the faults clears...

[Maxmekker1971]

Did you ever find s solution to this?

[Meat-Head]

ON TOPIC:-

Due to coronaberg 18 virus. You will have to experiment

disasemmble instrument cluster and look for “black mould” like you find in your bathroom
on both sides the circuit board, get fine sandpaper and rub away, then spray with lacquer

see what happens

[volorucinski]

Did you try with ABS module?
Try unjacking it, see if some of the faults clears...

If there is no problem inside ecu, then go and unplug the abs pump socket and bridge the 2 can wires can h and can L to make continuity

[omglol]

Did you ever find s solution to this?

Yes. Cracked IC inside ECU (the one that handles CAN traffic besides other stuff). I bought used ECU, cloned old one and - (just for the Meat-Head) - PRESTO ! - problem solved.

[hopsis]

I have a '02 Stilo. Steering column was broken, I swapped it with a used part. Now the steering works perfect but all control units give error codes U1700, U1702 and U1706. All are related to can bus communications.

I have so far measured all the can lines from every control unit, verified good connections at D4 (0.2-0.3 ohm resistance on all can hi/can lo wires), tried unplugging various units from can bus. If I take out the small 10-pin connector at steering column control unit and use jumper wires to bridge can hi/can lo lines, all other error codes go away and only the code for missing connection to steering column control unit remains (of course, because the connector is not connected to the unit). That leads me to believe the fault is at the "new used" steering column.

The bus itself seems fine and intact. Resistance is 60 ohms and can line voltages add up to 5V, I don't have an oscilloscope so measured only with a multimeter.

The only thing giving me trouble is the new steering column, old column is completely dead so I cannot even use that to check if the errors go away. K-line diagnostics work fine and the steering also works just fine, the only real problem is the error codes for lost communications and the resulting engine warning light in the dash. Any ideas? Can I replace the can controller from old steering control unit to the new? I have a decent soldering station but don't know how to regognize the component or maybe it's built in to the processor?