limp mode in w129 500 sl

[dinoy]

a friend has sl 500 1996 which is playing up, sometimes when starting in cold weather it goes into limp mode, once battery leads disconnected for a period of time then reconnected the car starts ok and drives fine.

we thought it was battery was needed changing, once changed everything reset lights under the mirror red and green flashed a few times when key was in and eventually it reset and started without a problem.

we left it a few days with the new battery tried to start it today again back to lump mode.

the fuel tank as 3/4 as he had similar problem when petrol was low which was resolved by adding more petrol into the car.

just had the old battery recharged last 48 hours, as it is probably not a battery problem.

any directions tricks is much appreciated. we are hoping this is not a ecu problem

 

[dinoy]

tehe limp mode light in question are epc and asr

fitted old but charged battery same problem again.

drivers window went down half way!!

started first time with a few turns on the starter and limp mode.

switched off started again and limp mode again!

proceeded to put windows down twice from memory this resets the 1/2 cm down on open. which worked!!

this time the car was running in limp mode for a while.

stopped and restarted it again not in limp mode anymore, and drove it and it was fine.

it is a very odd any clues ideas pls

 

[dinoy]

bump up, so far car starts every morning not in limp mode. come on guys any ideas

 

[dinoy]

turned out to be the throttle problem once cleaned and errors removed it is running fine