Rev counter problem ??

[Redrick]

Good afternoon chaps

Long time lurker but not much of a poster however I wonder if any one can help with this problem

The Rev counter on my D4d LC4 ( Auto) is behaving strangely

started today over reading by a at least 1000 RPM. Even with the engine off it is indicating just over 1K

Worrying seeing it in the red at 50 MPH in top gear

Any ideas ?

 

[Rob Cowell]

Good afternoon chaps

Long time lurker but not much of a poster however I wonder if any one can help with this problem

The Rev counter on my D4d LC4 ( Auto) is behaving strangely

started today over reading by a at least 1000 RPM. Even with the engine off it is indicating just over 1K

Worrying seeing it in the red at 50 MPH in top gear

Any ideas ?

I'm assuming it's doing this with the ignition on and engine off?

It's going to be the tacho itself (which is all part of the combination meter containing the speedo, fuel guage etc). Or it's the engine ECU. Or it's the cable between them.

The diagnostics for this involve attaching an osciliscope to the plug that connects to the combination meter. Dodgy waveform means its the ECU. Good waveform but continuity between specific pins on the combinantion meter means it the meter. Otherwise it's the cable.

If you PM me your email address I can send you the details on exactly what to test.

 

[Redrick]

I'm assuming it's doing this with the ignition on and engine off?

It's going to be the tacho itself (which is all part of the combination meter containing the speedo, fuel guage etc). Or it's the engine ECU. Or it's the cable between them.

The diagnostics for this involve attaching an osciliscope to the plug that connects to the combination meter. Dodgy waveform means its the ECU. Good waveform but continuity between specific pins on the combinantion meter means it the meter. Otherwise it's the cable.

If you PM me your email address I can send you the details on exactly what to test.

Cant PM you but my E mail is

Many thanks

 

[Rob Cowell]

Cant PM you but my E mail is xxx@xxx

Many thanks

What year is it? Combi meters changed in August 2004.

 

[Redrick]

What year is it? Combi meters changed in August 2004.

Its a 2006

Thanks

 

[Rob Cowell]

Let me know if you get to a link I haven't sent you. Also worth editing your post to remove your email address. Save a nasty harvesting algorithm stealing it for spam.