Limp Mode, drive system fault and stop start error.

[Johnny potts]

Hi Guys,
As the above suggest, I keep getting a stop start error and a drive system fault error. The EML did come on and I have reset this since and not had an issue since.

Switching the car on and off and both issues disappear. Could be for 2 minutes or two hours driving.

Now I think the culprits the battery, it’s down to 76% capacity, holds at 12.2 when it’s off not 12.4 and Max’s at 13.3 on load. Reading online I’ve seen this causing a few issues with other S4 B9s

but I want to drop a message on here first before replacing the battery to see if anyone else has had this issue before.

Specs:
2017 S4 Avant
Intake
Tuning Box (yes another thing coming off possibly rule it out)
49k

all the best

 

[NHN]

Stick a ctek on it for a day or so to recon the battery, see if it helps, xms 5 or 1 that does 8 stage.

 

[DavidStarkey11]

I am running a DTUK tuning box. One morning upon start up I got the same error as yourself and the car was running/ accelerating very lumpy. I ran a quick scan with OBD11 and I got the following faults:

• P010600 - Manifold Abs.Pressure or Bar.Pressure
• P023600 - Turbocharger Boost Sensor (A) Circ.
• P017100 - Fuel Trim,Bank1 (System too lean)
• P217800 - System too rich off idle, Bank 1

Glancing at those errors I knew it has something to do with the tuning box. I contacted DTUK and they suggested cleaning the loom and all connectors. I bought some WD40 electrical contact cleaner and cleaned the loom. I refitted it back to the car and so far *touches wood* it has been fine. This was about 4 months ago now.

 

[NHN]

Probably just needed the pins to be cleaned, it happens, had a similar experience with client & his dimming mirrors, although when I left they were working perfectly, if it's been sat connected for a while & you disconnect, sometimes the pins have a bit of surface build up from heat & it disturbs the conduction so to speak, I guided my client how to remove mirror, then unplug, plug & all is well again, it's not so uncommon, but I'll say this on an 8Y that's a little bit too soon to experience that kind of situation unless the dtuk box pins weren't as clean as they should be, sitting on a shelf in damp storage etc & then dryness.

 

[Earton]

I am also running a DTbox on my car and had this issue come up. I contacted DTUK who told me it was likely a poor connection between the large plug and the box itself. They asked if it had an orange rubber gasket where it plugged in and if it did remove it. I did as instructed and have never had the error since.

 

[DavidStarkey11]

I am also running a DTbox on my car and had this issue come up. I contacted DTUK who told me it was likely a poor connection between the large plug and the box itself. They asked if it had an orange rubber gasket where it plugged in and if it did remove it. I did as instructed and have never had the error since.

Ah good shout. I'll definitely try that next time if the error occurs again.