Technical Comfortmatic

[ajward]

Hi I have no auto availability on my comfortmatic gear box

 

[ajward]

I have also changed the break pedal switch after having a diagnostic check carried out that highlighted two fault codes po857-86 and po856-81

 

[MSjoberg]

T

I have also changed the break pedal switch after having a diagnostic check carried out that highlighted two fault codes po857-86 and po856-81

Those codes relate to communication from the Brake System Module (BSM) to Comfortmatic module.

 

[ajward]

T

Those codes relate to communication from the Brake System Module (BSM) to Comfortmatic module.

View attachment 464872

View attachment 464871

 

[ajward]

Thanks you so much msjoberg your information is very much appreciated many thanks ajward

 

[ajward]

I will get it booked in as I don’t have the equipment to to check it out fingers crossed it’s not to expensive

 

[ajward]

Hi there just had a further diagnostic test carried out on the motorhome today and it’s now free of any error codes so all is good there but motorhome is only still drivable in manual the comfortmatic gearbox will not allow me to select auto any thoughts you have would be appreciated.

 

[MSjoberg]

What first comes to mind: error in Gear Lever Sensor(s), or in wiring from Gear Lever Sensor(s) to Transmission Control Unit, or in Transmission Control Unit.

Speculating further: If there are no error codes it seems to be some error that the system doesn´t detect, this could point to some mechanical error preventing the function of the Gear Lever Sensor for auto/manual selection. I do not know which one of the sensors this is.

I would start with a simple test using Multiecuscan or other capable diagnostic tool, to check the status of the Gear selector lever position parameter when auto/manual is toggled with the lever.

Error codes when errors are detected for the sensors:

 

[ajward]

Thanks again for you thoughts it’s very much appreciated I will keep you posted.