One for the re-mappers out there

[sidepod]

One of my YouToob rabbit holes is diagnostic videos.

A recent one flagged up an issue with remapped vehicles.
Basically what happens with these units, when connected to a scan tool is, the ecu, having recognised it no longer has the original software, takes the opportunity to both stop logging fault codes and, more importantly, stops the vehicle from starting.

The absence of fault codes makes it extremely difficult to diagnose. The guy making the video said his first question is always “is it remapped “ and if so, refuses to work on it.

Apparently the reason the ecu no longer stores fault codes is, during the mapping process the original parameters are raised/lowered etc. it’s these parameters that set the codes so the mapper has to disable this function.

I’ve run cars with re-maps without issues but I’ve never been in a situation where I’ve plugged in diagnostic scanners.

Interesting but not surprising.

Anyone confirm? Anyone had an engine issue but no fault codes present?

 

[colintfcolintf]

Long term Pendle remap on my XLWB sprinter - no issues

 

[WelshGas]

One of my YouToob rabbit holes is diagnostic videos.

A recent one flagged up an issue with remapped vehicles.
Basically what happens with these units, when connected to a scan tool is, the ecu, having recognised it no longer has the original software, takes the opportunity to both stop logging fault codes and, more importantly, stops the vehicle from starting.

The absence of fault codes makes it extremely difficult to diagnose. The guy making the video said his first question is always “is it remapped “ and if so, refuses to work on it.

Apparently the reason the ecu no longer stores fault codes is, during the mapping process the original parameters are raised/lowered etc. it’s these parameters that set the codes so the mapper has to disable this function.

I’ve run cars with re-maps without issues but I’ve never been in a situation where I’ve plugged in diagnostic scanners.

Interesting but not surprising.

Anyone confirm? Anyone had an engine issue but no fault codes present?

Not something I've seen mentioned on the T6 Forum.

 

[sidepod]

Long term Pendle remap on my XLWB sprinter - no issues

So you’ve had it back to the main dealer, diagnostic scanner plugged in, as I asked?

 

[Black Forest]

Long term map on a VW Caddy (160k kms). No issues, scanned using teh VW tools and passed the dreaded TüV every time for 6 years or so.

 

[colintfcolintf]

So you’ve had it back to the main dealer, diagnostic scanner plugged in, as I asked?

So you’ve had it back to the main dealer, diagnostic scanner plugged in, as I asked?

MOT & service yearly at a very highly rated Merc independent with no issues

 

[paul_f]

Poor quality remaps just inhibit any fault code from appearing, which can then make it very difficult to diagnose a failure. That's what the guy in your video is referring to.
It's not deliberately performed by the ECU or OEM