a140 wont give any diagnostic codes

[zinnia48]

Hi,
I have a w reg a140. it has always shown diagnostic codes when i have taken it to my local garage. Recently wont start, however when plugged into garages diagnostic machine wont connect or show any codes, had another garage bring his delux equipment still wont give up any codes, in fact squat all. Engine turns over ok, but wont start , neither will it bumpstart.

Has anyone any ideas about what could be causing engine not to be showing any diagnostic codes

many thanks

 

[AMG19]

Are they Mercedes Specialists using a star machine?

 

[zinnia48]

Not sure what the diagnostic kit being used is , but the main thing is that they have regularly obtained diagnostic information from the a140 in the past to analyse several problems. So the kit is fine, the car is just not sending any info or not allowing any info to be read

 

[paul m]

coud be the main ECM engine control module under the bonnet right hand side, disconnect batt, unplug ecm check contacts refit plug, reconnect batt

 

[paul m]

Ecm plug disconnected
Term 57 11.14v ign off
Term 58 11.14v engine cranking
Term 48 11.14v ign on
Term 68 11.14v ign on
Term 69 11.14v ign on
engine control relay must be fitted and working to check for supply voltage voltages are typical values (good batt)

 

[paul m]

After checking voltages check earth on same plug
Term 40 to earth 0 ohms
Term 41 to earth 0 ohms
Term 47 to earth 0 ohms
This info is for A class (168) engine code 166.940