Technical Steering calibration issue

[pjs1978]

I have a 2008 Fiat 500 1.4 Lounge RHD with about 115k miles on the clock. Lovely little car owned for 3 years and hoping to get a few more years out of it. Currently doing a few pre-MOT bits of work (due early May) and have run into a problem with steering calibration.

For a while the steering wheel has had a little bit of play in it, so I decided to look at the intermediate shaft as I’ve seen reports of these being the cause. It turned out the top bolt had worked loose and needed tightening, but whilst I was at it, I decided to take the entire column out to check for play in the joints. Note that I disconnected the battery beforehand to prevent the airbag deploying.

Intermediate shaft was fine and went back in ok and I did my best to keep the steering wheel aligned. Battery was then reconnected and decided to go for a test drive, but as I pulled out onto the road the ESP and HH unavailable error messages flashed up on the display. Steering felt smooth but then a bit lumpy when applying high steering angle input. On the plus side the original wheel play has gone. Once on the open road the car drives perfectly.

Back on the drive I tried a few wheel lock-to-lock steering relearn attempts without success. I then tried disconnecting the battery for 45 mins to reset everything with no joy. I have a full licence of MES with coloured connectors which came back with the following errors:

• U0019-01 – B-CAN line – General electrical failure
• C0051-54 – steering angle sensor (NGE) – Missing calibration
• C1008-54 – Positon sensor calibration – Missing calibration

The codes were cleared in MES, but then re-appear on startup when moving the steering wheel.

After further research I tried a PROXI alignment using MES. This was deemed to be not needed by MES, but I managed to perform it anyway. I’ve also made several attempts to run the steering calibration in MES but it always returns a message stating 'conditions not met'. Note that steering wheel and road wheels are straight and my drive is level when attempting the calibration.

I’ve checked the battery (Lucas, 3 years old) and it is giving 12.83v at rest and 14.26v with the engine running. Earth strap was replaced 3 years ago and there have been no other electrical issues prior to this calibration problem.

Any suggestions on a way forward are welcome!

 

[A3jeroen]

Did you by any chance turn the steering wheel 360 degrees before putting it back in? IIRC it is impossible to be 1 tooth out on the steering since everything goes in one way.
Being 360 degrees out is risky because of the clockspring wiring.

gr J

 

[pjs1978]

Did you by any chance turn the steering wheel 360 degrees before putting it back in? IIRC it is impossible to be 1 tooth out on the steering since everything goes in one way.
Being 360 degrees out is risky because of the clockspring wiring.

gr J

I remember wiggling the wheel to get the shaft joint to locate, but not by a full rotation. I had another go with MES this morning and looked at the parameters menu which shows the steering angle is ~720 degrees (2 turns?!), so this explains why it won't perform the calibration. The steering angle reading moves with the wheel, so the steering angle sensor is working. Any thoughts how to reset the wheel to 0? I thought about disconnecting the lower intermediate shaft joint and rotating the wheel until it gets to 0 in MES, but concerned about effects on clock spring.

 

[A3jeroen]

Can you check the clockspring(wiring) when you remove the airbag?

gr J

 

[pjs1978]

On paper I think I have worked out a way to fix this by removing the wheel, disconnecting clock spring, then using MES to calibrate the steering angle sensor while the shaft lower joint is disconnected. Will give it a go this weekend and report the outcome.

 

[pjs1978]

This morning I had another go and the problem is now fixed. No more warning lights and steering feels normal again. For future reference, this is the procedure I used:

1. Straighten road wheels and steering wheel
2. Disconnect battery
3. Remove air bag
4. Disconnect clock spring connections and remove steering wheel
5. Disconnect lower steering shaft joint
6. Reconnect battery
7. Clear any steering errors using MES
8. Using MES steering angle sensor reading, twist shaft until it reads 0 degrees
9. Run steering angle calibration in MES
10. Disconnect battery
11. Reconnect lower intermediate shaft joint
12. Refit wheel, clock spring connections and airbag
13. Reconnect battery and test steering.