Hi Guy,
Looking for some advice on where to go next with my SMG repair.
I was driving home last Monday when my 2003 Z4 3.0i SMG, automatically shifted from 5th to 4th and the transmission light came up on the dash. The paddles could not change the gears, and even as i pulled over the car didn’t auto shift down. I had the car recovered to my local independent BMW garage.
They checked for errors and could see that there was an "Internal Fault" on the SMG ECU. I bought a replacement SMG ECU from an eBay shop who sells BMW parts.
The part arrived the next day and they fitted & programmed it. I got a phone call to advise that the car is changing gear, but not smoothly or quickly. Surprisingly the following day I was called and told that I could collect the car. I paid and drove the car away. As I drove off I could tell that the gear change wasn’t right. It felt like the car would change gear ok, but then not reengage the clutch for 5 seconds, during this time the car would coast. The car broke down within 30min of driving. Luckily after 20minute with he engine off the fault cleared and the gearbox allowed me to drive it back to the garage.
Now the garage is not sure what to change next as there aren’t anymore errors logged in the management system.
They did point out, at time of fitting the SMG ECU, that the ECU already had 3 slots programmed and therefore couldn’t be brand new. Is it possible that this unit may also have a fault they is affecting the gear change?
The garage has suggested changing the Shift Angle & Shift Selection Sensors, but this requires removing the whole gearbox. Plus there is no evidence that this will even fix the issue.
Gavin
Looking for some advice on where to go next with my SMG repair.
I was driving home last Monday when my 2003 Z4 3.0i SMG, automatically shifted from 5th to 4th and the transmission light came up on the dash. The paddles could not change the gears, and even as i pulled over the car didn’t auto shift down. I had the car recovered to my local independent BMW garage.
They checked for errors and could see that there was an "Internal Fault" on the SMG ECU. I bought a replacement SMG ECU from an eBay shop who sells BMW parts.
The part arrived the next day and they fitted & programmed it. I got a phone call to advise that the car is changing gear, but not smoothly or quickly. Surprisingly the following day I was called and told that I could collect the car. I paid and drove the car away. As I drove off I could tell that the gear change wasn’t right. It felt like the car would change gear ok, but then not reengage the clutch for 5 seconds, during this time the car would coast. The car broke down within 30min of driving. Luckily after 20minute with he engine off the fault cleared and the gearbox allowed me to drive it back to the garage.
Now the garage is not sure what to change next as there aren’t anymore errors logged in the management system.
They did point out, at time of fitting the SMG ECU, that the ECU already had 3 slots programmed and therefore couldn’t be brand new. Is it possible that this unit may also have a fault they is affecting the gear change?
The garage has suggested changing the Shift Angle & Shift Selection Sensors, but this requires removing the whole gearbox. Plus there is no evidence that this will even fix the issue.
Gavin
