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Discussion Starter #1 (Edited)
I have been having troubles with the ABS ECU since I got my '02 156 1.9JTD. the first ECU was not working so I changed it.
ABS works fine, but I still have problems with VDC, EBD and ASR, none are working. I had a faulty clock spring and a faulty steering wheel position sensor so I changed those and I calibrated the steering wheel pos sensor with multiecuscan. But everything is still not working. when I scan for errors is shows Engine>ABS data line and the ABS light comes on in the dashboard(it shuts off as soon as I disconnect the ECU from my PC).
vehicle speed shows 15km/h and sometimes 240km/h, but most of the time it is 15km/h while the car is not moving(in multiecuscan, not in speedometer, the speedo is fine).
Drain valves, load valves and traction solenoid valves are all OFF even when I start moving, is it normal ?
Clutch pedal sensor is faulty, and it shows that it is pressed while it is not.
I have no idea where the clutch pedal sensor is located, drain valves/load valves or traction solenoid valves, and why is the vehicle speed signal is faulty while the speedometer shows the correct car speed.

some attached pictures that show what I got in multiecuscan.
 

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The clutch pedal is easy and common. It's a bayonet fit switch (usually white) tucked up above the clutch pedal, with a self-adjusting peg that is pushed in by a plate on the pedal pivot when the pedal is up. To fix it, remove the switch by rotating the body 90 degrees and lift upwards. Then grab the peg with pliers or a vice and pull quite hard, until it is extends about 12mm from the body. Now put the switch back with the pedal depressed, and the peg will be correctly adjusted as you release the pedal.

If that doesn't fix it, you need a new switch - but mostly it's just that the peg had got pushed too far in during work on the clutch and simply needs resetting by yanking it out.

As to the rest: beyond my competence. AFAIK 156 doesn't have CANbus, so I'm not sure what MES is seeing. Someone will know better than me.
 

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Discussion Starter #3
Thank you for your reply I will try what you said.
Also, what is Flow modification throttle ? someone told me it is related to cruise control,I don't have the cruise control stalk on my car, but the the cruise control light is ON in the dashboard(yes you got that correctly). I don't know if the previous owner changed the dashboard or something...
I have one radiator fan and it is working great, I changed both the radiator and fan because it didn't have the original ones before.
 

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Drain, load and traction solenoid valves are inside the ABS control module.

I'm guessing that you have VDC, EBD and ASR fault messages showing, but no ABS fault message ? Sounds odd, I'd have have thought if those were failed ABS would be also. Unless the "Engine>ABS data line" problem means the ABS ECU can't connect/interact with the engine ECU to control those functions correctly (power control) so they've shut off.
 

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Discussion Starter #5
Drain, load and traction solenoid valves are inside the ABS control module.

I'm guessing that you have VDC, EBD and ASR fault messages showing, but no ABS fault message ? Sounds odd, I'd have have thought if those were failed ABS would be also. Unless the "Engine>ABS data line" problem means the ABS ECU can't connect/interact with the engine ECU to control those functions correctly (power control) so they've shut off.
VDC error shows in the infocenter as well as EBD,but ASR doesn't, just it's not working, the ASR is always off. ABS works fine and its light doesn't light up on the dashboard(except when I connect the ABS ECU to multiecuscan).
 

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On a CANbus car I'd wonder if there was an ABS computer problem or it needed a proxy alignment - a flashing odometer would indicate that. However, 156 isn't CANbus, it's Datalink or something, which is similar to CANbus but different, and I know nothing useful about it. However you did say you replaced the ABS pump/ecu in msg#1. Was it the exact same part number as your original? Is it possible you've fitted a unit from a later CANbus car like a GT or 147? That might be only partly compatible and give odd results. Or I might be talking rubbish and it's impossible to plug a CANbus ABS into a 156...
 

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As Halftone said, are you sure that the replacement ABS module was the EXACT same model? I replaced one on my old GTV TS and there was a good 5 or 6 different ECUs used that were all similar but it was necessary to make sure you had the exact part # and that took a lot of searching until I managed to find the correct unit.

The errors seem to indicate to me that the ABS ECU is either faulty or not communicating correctly with the body ECU. When my unit went on my GTV I had solenoid valve errors and wheel speed anomalies and the ABS would still work periodically despite them. The only solution was to replace the unit with the correct replacement and then I never had another issues after that.

Do you happen to have the old module still lying around so that you can double check the part number with the replacement you bought?

Before you go any further though, are you positive that your battery is in good condition? Whilst I don't think it is battery related, a weak battery can throw up all kinds of strange errors. It should be reading >12.6v with the ignition off and is a simple check with a multimeter. So maybe start with a simple battery check and then start turning your attention towards the ABS module if the battery checks out.
 

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Discussion Starter #8
About the ABS ECU, I got one from the same car as mine first facelift 1.9JTD 8v, just when connecting to multiecuscan it tells me that the ISO number is not matching .. but i carry on diagnostics with no problem. the ABS works fine and it was the main reason why I replaced the ABS ECU. The car I took it from had the same model number (932A2C0...)
I did not perform a proxy alignment as I don't see it in multiecuscan, my battery is in good condition.
 

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About the ABS ECU, I got one from the same car as mine first facelift 1.9JTD 8v, just when connecting to multiecuscan it tells me that the ISO number is not matching .. but i carry on diagnostics with no problem. the ABS works fine and it was the main reason why I replaced the ABS ECU. The car I took it from had the same model number (932A2C0...)
I did not perform a proxy alignment as I don't see it in multiecuscan, my battery is in good condition.
That could be an issue potentially. Just because its from the same car doesn't mean its the exact same module. Even being the same year and engine version doesn't mean it is. Alfa seemed to just use whatever they found lying around at the time. I can't say for certain that this is your issue but I am leaning that way.
 

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Discussion Starter #10
That could be an issue potentially. Just because its from the same car doesn't mean its the exact same module. Even being the same year and engine version doesn't mean it is. Alfa seemed to just use whatever they found lying around at the time. I can't say for certain that this is your issue but I am leaning that way.
the fact that ABS works fine makes me think that there's no problem with the ABS ECU, but that could be possible anyway.
How to perform a proxy alignment ? I tried to do it before but I don't see it in multiecuscan(I have a registered copy)
 

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Pretty sure the 156 doesn't need Proxy alignment since it doesn't have a body computer.

As said above, VDC and ASR requires the ABS module to talk to the engine ECU to control power. If the ABS ECU can't talk to the engine ECU it will shut off the functions that need power control whilst still allowing the basic ABS function to work because there's no power control involved. Not sure about EBD. Seems it does more than just rear brake balance, something to do with VDC when cornering so may also need power control to work properly.
 

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I suspect the Iso id error is a clue. It sounds analogous to a CAN ID on a canbus car. Might mean that the ABS is a subtley different type, or that some software integration is needed, similar to Proxy, but with main ECU. If MES can't do it I wonder if it's an Alfa dealer procedure. All wild guessing, but from Google the Bosch 5.7 ABS is rather prone to failing due to connections within the ECU. and heat related.
 

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Discussion Starter #14
how can I inspect the connection between the engine ECU and ABS ECU ? I have no idea what to look at. relays? cables? any suggestions would be appreciated!
 

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I believe the ABS ECU is mounted to the ABS unit, with a plug to the loom on the underside. Worth checking for dirty connections There is also a relay somewhere. You may find out more here LMGTFY
 
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