Technical help! Many dash lights, many messages, U1706 error code.

[Herts Hillhopper]

Start at the end - I doubt MES can tell you much more but might focus a little by adding the missing two-digit code that should follow the letter and four numbers you’re seeing now. It might be better able to report the ABS and Airbag codes too.

The U Codes are (I think) ‘safety’ related (ABS, airbags etc). There’s been another thread here where the cause was a damaged wire from the seat occupancy switch where the wire had been caught in the seat runner or through something being pushed under the seat. (Was that this thread??). It led to various spurious other codes which were all red herrings.

 

[Panda IIs]

Suggestions please of what/where to look next?
- Where is the BCM on these? And where does the loom for it run?
- @Herts Hillhopper you mentioned the ABS ECU too, but more likely associated wiring. Where to find ECU and loom path?
- What else could I be looking at?
- Will MultiECUScan be likely to give more detailed insight?


Many thanks, Jamie

I can't add much other than to say the BCM is up under the glove box on RHD cars, you can see by pulling back the carpet/sound insulation on the passenger footwell and laying on your back! It's not so difficult with the glove box removed From my experience of getting keys programmed there are two suppliers Marelli and the other one whose name escapes me right now, anyway that doesn't really add much to the discussion.

 

[Herts Hillhopper]

I can't add much other than to say the BCM is up under the glove box on RHD cars, you can see by pulling back the carpet/sound insulation on the passenger footwell and laying on your back! It's not so difficult with the glove box removed From my experience of getting keys programmed there are two suppliers Marelli and the other one whose name escapes me right now, anyway that doesn't really add much to the discussion.

You can see the BCM by opening the little hatch at the back of the glovebox — the fuses are mounted in the BCM unit. I don’t know where the ABS ECU is, but believe the airbag and SRS one is on the car floor beneath the heater.

 

[Panda IIs]

You can see the BCM by opening the little hatch at the back of the glovebox — the fuses are mounted in the BCM unit. I don’t know where the ABS ECU is, but believe the airbag and SRS one is on the car floor beneath the heater.

A few words of caution: Re the SRS module/sensor do not detach anything from the vehicle frame with the battery connected in case it is the yaw/deceleration sensor - that can be bad news in some situations... (I don't have specific FIAT experience).

 

[Herts Hillhopper]

A few words of caution: Re the SRS module/sensor do not detach anything from the vehicle frame with the battery connected in case it is the yaw/deceleration sensor - that can be bad news in some situations... (I don't have specific FIAT experience).

Yes. Disconnect the car battery and leave it a while for any residual charge in the SRS system to dissipate.
Generally, anything related to the SRS system has yellow connectors, yellow cable sleeves or yellow wires.
Pete

 

[Herts Hillhopper]

My earlier reply was based on my memory… which isn’t always a good idea I see it was indeed this thread where I linked to another with seat occupancy detector being at fault!

U codes are ABS but not airbag related. Because it’s not an ‘engine’ code, this won’t trigger the ‘engine’ light — that (should) only come on to show a fault that can affect the emissions control systems.

Code U1706 is (apparently) an ABS system fault, and specifically a failure of the CanBus connection between the ABS’s ECU (which is integrated into the pump unit at the back, passenger side of the engine bay) and the BCM inside the car.

But you may already have been told that too?

 

[Jamie KC]

Yes. Disconnect the car battery and leave it a while for any residual charge in the SRS system to dissipate.
Generally, anything related to the SRS system has yellow connectors, yellow cable sleeves or yellow wires.
Pete

Thanks, and @Panda IIs also.

I'm a big believer of disconnecting the battery for a lot of work. And a big fan of the quick disconnect post on the Panda too!

For SRS related systems is it necessary to disconnect the other terminal as well for the stop/start voltage sensor? Or will the main post suffice?

 

[Jamie KC]

My earlier reply was based on my memory… which isn’t always a good idea I see it was indeed this thread where I linked to another with seat occupancy detector being at fault!

U codes are ABS but not airbag related. Because it’s not an ‘engine’ code, this won’t trigger the ‘engine’ light — that (should) only come on to show a fault that can affect the emissions control systems.

Code U1706 is (apparently) an ABS system fault, and specifically a failure of the CanBus connection between the ABS’s ECU (which is integrated into the pump unit at the back, passenger side of the engine bay) and the BCM inside the car.

But you may already have been told that too?

Will be under it on Sunday to look for any harness related issues in the engine bay. The gearbox etc has all been disturbed for a clutch replacement, and there were a number of things the garage hadn't done well on reassembly, so perhaps there is another related problem here? Will also try to get a good look at the ECU connectors to ABS and BCM, if accessible enough.

Will revisit that thread, but all looked well under the seats. Cheers.

 

[Panda IIs]

Will be under it on Sunday to look for any harness related issues in the engine bay. The gearbox etc has all been disturbed for a clutch replacement, and there were a number of things the garage hadn't done well on reassembly, so perhaps there is another related problem here? Will also try to get a good look at the ECU connectors to ABS and BCM, if accessible enough.

Will revisit that thread, but all looked well under the seats. Cheers.

Good call; I'm not a great believer in "coincidence" if issues are following previous work.

Perhaps there is an issue with the ABS ring/sensor if a bit of a "do" was had with a driveshaft??

Also better code reader may help?

 

[Herts Hillhopper]

Thanks, and @Panda IIs also.

I'm a big believer of disconnecting the battery for a lot of work. And a big fan of the quick disconnect post on the Panda too!

For SRS related systems is it necessary to disconnect the other terminal as well for the stop/start voltage sensor? Or will the main post suffice?

I suspect the 'other end' of the monitoring using is connected to the positive of the battery (rather than to the body shell/earth) so it can register the voltage? Removing the main earth should be enough I'd have thought. (But now you've made me wonder...)

 

[koalar]

Not sure where this thread is going

P0555 is the brake boost sensor

On the vacuum hoses going to servo manly fitted to diesels

Something like this part 2

You could try unplugging it electric connector,.I don't have a diesel to try but guess it can be tested with a multimeter, assuming it's not vacuum leak

But it's in the same rough area as the ABS fault in the post below

 

[koalar]

Immediate U1706 code on start up even after clearing

ABS to ECU communication error

Speedo not working, odometer not increasing,

Wheel sensor to ABS to dash

The common denominator is the ABS

Its close to the gearbox I'd check the cabling

And the boost switch

I will leave it the the 319 owners now i normaly only work on older cars

 

[Herts Hillhopper]

General agreement here: ABS sensor(s) or the ABS system wiring. You said earlier that the ELD was locked in too -- that also relies on signals from the ABS senders for its control circuit.

The other codes and errors may well be red herrings. But suggest a possible sensor wire shorting to the metalwork somewhere and causing 'wrong' readings to be shown.

 

[Jamie KC]

Thanks gents. I’ll be getting underneath it tomoz to poke around.

 

[Jamie KC]

So last Sunday didn't yield much of interest. I got as far as inspecting the ABS sensors and wiring, and was then distracted by worn front arm bushes and stabiliser links with rusted studs and nuts, plus spending time with the kids.

But yesterday it all changed - The drive to work was the usual, all the lights on, many warnings on the dash, no speedo etc...

But, I left work, got in the car and as I set off I noticed there were less lights on. Steering light, EM light and warning triangle still on, but ESC, ABS and handbrake/fluid light were out. Messages were to check steering, and stop/start disabled. And now the speedo was working, the external temp was displayed again, and the trip computer functions were re-enabled.

I parked up for a pint on the way home, and when I got back in and started it again the steering light stayed off as well, and I only had the stop/start disabled message.

I cleared the fault codes and restarted it, no more stop/start msg, and stop/start was functioning correctly.

In some ways this is positive because the problem has gone away, but it also means it may come back, as I haven't been able to diagnose the cause.

The only thing that has been any different is the weather! We've had the best part of a week of no rain, and the temps even just about saw 20deg yesterday.

Will see how it is today...

 

[Panda IIs]

So last Sunday didn't yield much of interest. I got as far as inspecting the ABS sensors and wiring, and was then distracted by worn front arm bushes and stabiliser links with rusted studs and nuts, plus spending time with the kids.

But yesterday it all changed - The drive to work was the usual, all the lights on, many warnings on the dash, no speedo etc...

But, I left work, got in the car and as I set off I noticed there were less lights on. Steering light, EM light and warning triangle still on, but ESC, ABS and handbrake/fluid light were out. Messages were to check steering, and stop/start disabled. And now the speedo was working, the external temp was displayed again, and the trip computer functions were re-enabled.

I parked up for a pint on the way home, and when I got back in and started it again the steering light stayed off as well, and I only had the stop/start disabled message.

I cleared the fault codes and restarted it, no more stop/start msg, and stop/start was functioning correctly.

In some ways this is positive because the problem has gone away, but it also means it may come back, as I haven't been able to diagnose the cause.

The only thing that has been any different is the weather! We've had the best part of a week of no rain, and the temps even just about saw 20deg yesterday.

Will see how it is today...

Some of what you describe is typical of a low volts battery - random sensor "faults" and especially Stop/start not available. You give a clue that the weather has perked up, so no wipers, probably the the heater fan and maybe headlights so perhaps the battery is in recovery? Or the alternator is not in the best of health?

 

[Jamie KC]

Some of what you describe is typical of a low volts battery - random sensor "faults" and especially Stop/start not available. You give a clue that the weather has perked up, so no wipers, probably the the heater fan and maybe headlights so perhaps the battery is in recovery? Or the alternator is not in the best of health?

This is something that constantly niggles at me, as I am aware these cars are sensitive to low voltage issues.

So the car was all good on Saturday night, but on Sunday morning it was back in full Christmas Tree mode and beeping all the warnings at me again.

Here are the reasons I think it isn't a battery issue:

- I had a failing battery on for 12 months, often dropping to 12v or occasionally under, and the only issue resulting from that was Stop/Start unavailable.
- The battery was renewed in December, Yuasa EFB027 Stop/Start Battery, so a decent one.
- Charge rate is typically 14.6v (at least at the times when I test it, I check at idle and at 2500rpm) without load.
- I charged the battery overnight a few weeks back when I first encountered this issue.
- I connected the charger on Sunday after it went back to behaving badly. The diagnostic display showed 100%, and on starting the charge it turned itself off again relatively quickly in recognition of a full charge.

BUT, checking the resting voltage this morning showed 12.46v which, although not particularly low, isn't the 12.6 plus I would like to see. So .

There is definitely a temperature factor involved. Yesterday was another day approaching 20c in Cumbria, and on the drive home various lights went out, this time with the exception of the PS light which remained on, and the steering message was displayed. Cleared the codes again and S/S came back online.

The interesting thing this time is that when manoeuvring the ESC light very briefly flashed up, this triggered the warning light and knocked S/S offline again, I wonder what that means...?

 

[koalar]

U1706
Speedometer
ESC
Electric power steering
Start stop
P0555
Rear diff

All communicate and use information via the ABS module

Harness
4x sensors
ABS Module
4x magnetic rings
Plus.more

Just for the basics there 10 parts

Connect to the ABS module and read the codes you have lights on they will be logged

It would be the first port of call for me, and see where it leads

Unplugging and reinserting the connector on the ABS is also .a good start giving the intermittent nature

 

[Panda IIs]

This is something that constantly niggles at me, as I am aware these cars are sensitive to low voltage issues.

So the car was all good on Saturday night, but on Sunday morning it was back in full Christmas Tree mode and beeping all the warnings at me again.

Here are the reasons I think it isn't a battery issue:

- I had a failing battery on for 12 months, often dropping to 12v or occasionally under, and the only issue resulting from that was Stop/Start unavailable.
- The battery was renewed in December, Yuasa EFB027 Stop/Start Battery, so a decent one.
- Charge rate is typically 14.6v (at least at the times when I test it, I check at idle and at 2500rpm) without load.
- I charged the battery overnight a few weeks back when I first encountered this issue.
- I connected the charger on Sunday after it went back to behaving badly. The diagnostic display showed 100%, and on starting the charge it turned itself off again relatively quickly in recognition of a full charge.

BUT, checking the resting voltage this morning showed 12.46v which, although not particularly low, isn't the 12.6 plus I would like to see. So .

There is definitely a temperature factor involved. Yesterday was another day approaching 20c in Cumbria, and on the drive home various lights went out, this time with the exception of the PS light which remained on, and the steering message was displayed. Cleared the codes again and S/S came back online.

The interesting thing this time is that when manoeuvring the ESC light very briefly flashed up, this triggered the warning light and knocked S/S offline again, I wonder what that means...?

OK, did Sunday's misbehaviour coincide with rain again? Just wondering if it might be wet related (which I think was your suspicion?) If it is just temperature that suggests a sketchy (high resistance) contact to me.

 

[Herts Hillhopper]

Yours is a 2014 car? That means it still has the Blue&ME radio/Bluetooth system.
These are known to develop a fault which slowly drains the battery even when everything is switched off. And also has a connection to the CanBus system (which can lead to issues of flashing odometers etc).

Is it possible that your issues relates to this in any way? Seems odd to generate an ABS fault code from that but given the weird way unrelated error can occur across these cars maybe not out of the question - and your error is related to CanBus communications. The main B&Me control unit sits under the drivers' seat and can be unplugged - but beware that doing that also then triggers errors! There are other threads around this forum that cover the Blue&Me issues.