Discovery TD5 - Error code 135

Folks - just had car on diagnostics for the ABS lights but also had the following code logged, "135 - Engine speed input signal dubious".
Now the whole car is a touch dubious but does anyone know what has caused this error ?
Thanks
Chris

Not sure what 135 is but the Engine speed input signal dubious sounds like Nanocom code 21-6 &/or 21-7

For info The TD5 ECU does not monitor fuel flow, or fuel pressure, so it cannot detect fuel starvation issues. Was it does notice though is that the engine RPM or road speed is not where it expects it to be for the selected throttle position & Logs a fault.

The road speed input signal is supplied by the ABS / SLABS ECU (if fitted) or else by the gearbox via a reed switch. Failure of this input should disable cruise control. Does yours work (if fitted)?

So a problem with the ABS system and/or a problem with the driver input (accelerator/fuel/air).

HTH

Chan

Sounds logical considering the problems I have had recently. Had to replace the air bleed valve as I needed to purge the fuel system every time I wanted to start the car. Also did the injector seals last week following a misfire and engine dying. All of these involved heavy use of the throttle while being jump started or towed to get started again. Also had an intermittent signal logged against an ABS sensor so all in all I have probably confused the ECU.
Looks like I might be about to have a wheel bearing fail soon - what joy !
Thanks for the reply Chan

chrimcne said:

Folks - just had car on diagnostics for the ABS lights but also had the following code logged, "135 - Engine speed input signal dubious".
Now the whole car is a touch dubious but does anyone know what has caused this error ?
Thanks
Chris

Click to expand...

The "engine speed input" is an input on ABS ECU Connector 0655/10 from engine ECU black plug pin 19 which is a digital signal for the tachometer too. Then "The engaged forward gear and (on manual gearbox models) the clutch status are computed from the engine data input, the engine speed input and vehicle speed."

The ECM calculates engine speed based on the crank position sensor's input

So IMO it was an incompatibility at one point between the ABS sensor input and the engine speed input which could have been generated by the clutch switch....or various other reasons

Anyway untill the tachometer is working well and the engine runs fine u dont have to bother with this fault code.