ead

My M5 in its first 2000 miles has twice had the 'Transmission Failsafe' warning appear, accompanied by a stern injunction to 'Drive moderately'. In neither case does there seem to have been any real problem. Likeliest explanation seems to be low battery voltage (the car stands unused for a week or three at a time) although I have heard mention of a firmware upgrade which may help.

Anyone else had a similar problem? Any thoughts on fitting a battery voltage meter? At least it would give some warning.

Ted Davison

nyc.turbo

I noticed that also on Saturday morning after a 45 min drive ,cel with a transmission warning. 2800 miles here, I think I`ll take her in on Thursday. I`ll take it easy until they check it out.

0700700

m5board.com .... speak to ashok arora

Edlee

Better take it in. I had this prob with my M6. It was caused by a DSC sensor which detects all other faults concerning the wheels of the car. Don't know what it is called, but it is a coded item and is not available off the shelf. Your dealer has to order it from BMW in Germany and that takes a few days.

cobradav

There is one service bulletin out that may or may not apply here:

SI B 23 01 06
Manual Transmission January 2006
Technical Service

This Service Information bulletin supersedes S.I. B23 01 06 dated January 2006.

(New) designates changes to this revision

SUBJECT
SMG III: Fault Code 5101 Analyze Hydraulic Sensor


MODEL
E60 M5

SITUATION
While driving, the SMG control unit may intermittently switch to the emergency program. The SMG module has Fault Code 5101 (Hex) "Analyze hydraulic sensor" and the environmental condition: "Hydraulic pressure sensor earth cable broken stored in memory.

CAUSE
SMG III module software diagnostics is too sensitive.

PROCEDURE
Perform "Short Test" and clear faults.

Do Not Replace Any Parts!

(New) Reprogram the vehicle using Progman V 20.1, or higher to Target Data status (E060-05-12-510)

(New) WARRANTY
For the appropriate labor operations please refer to the KSD system.

ead

Thanks to all who responded.

Dealer explained -vaguely - that a 'replacement cable' is needed. Due in a few days. Could this be a 'Hydraulic pressure sensor earth cable'?

Ted Davison

ead

Update...

Dealer now advises the problem is caused by a faulty battery lead. It seems that when an airbag is triggered, the system also cuts battery power (to reduce fire risk, I suppose). This is accomplished by a mechanism incorporated in a battery lead. The dealer's first attempt to obtain a replacement resulted in delivery of a complete wiring harness - 'The parts list is unclear, sir'. The correct part is now awaited.

The M5 is of course a truly great car but in 10 years of owning Lexus (3), Skyline (2), 300ZX and 350Z the worst trouble I had was a sticking boot lock.