Nagging Intermittent Problem

[IANH]

Hello.....I have just registered and looking for help.

My '56 e61 520d had recently gone into limp mode twice (two weeks apart).

Both times the EML came on for a split second then soon after the light indicating a DSC/DTC problem illuminated.

The car then slowed abruptly and the steering stiffened up.

Both times have been on busy roads.

Previous to these events I have glimpsed the EML for a split second accompanied by a slight pull back in power.....then all is well.

The only other problem I have had is a bad earth on a reversing light.

The car went into a main dealer for a diagnostic check. They reported certain faults but nothing that relates to the recent problems. They have cleared all error codes and advised that I drive the car until the problem returns.

Yesterday I removed the reverse light and cleaned it and ensured it was all good....with a smear of copper grease for good measure.

I am curious if anyone can shed light on the problem and whether something as trivial as a bad earth could ultimately cause my car to shut down?

When the car did shut down I was able to drive off ok. The warning lights also cleared themselves.

On the second occasion the central display reported "DBC failure, drive moderately". This also cleared itself when the car was next started.

I am also curious to know that if the problem does reappear and the error codes do not prove helpful then would a software upgrade be a good course to follow.

Many thanks.

[BigAl]

Welcome Ian, Sorry to hear you are having problems, yes a bad earth or loose wire can stop a car, I would check all the wiring to see if you can see anything obvious, also in the 1 and 3 series there is a pressure sensor that fails in the DSC, could be an idea for software upgrade, good luck.

[IanIOM]

This does indeed sound like a pressure sensor issue, I had the pleasure of one failing in a 3 series, steering came very heavy and it almost felt like the iginition had been turned off!

Sadly though there was no set of circamstances which made this fault occur, unless of course it was at that moment where I had just built faith back up in the little 3 then i would cause trouble