M104 HFM cruise control. Any problems if disconnected?

[hismajestics]

I have swapped a M104 from E320 into a W114 Coupe. It was originally a non-ASR car and 5 speed manual.

Now I'm facing some problems with the engine not revving (max 1500rpm i guess) and having high idle. When idling it runs very smooth. Can this symptom be due to a disengaged cruise control? I took away the control unit and wiring harness. Any connections that needs a signal from this control unit?

I'm aware of the rev limiter at 4000rpm if the car does not get a vehicle speed signal. I feel my problem is of some other kind. Thanks.

/johannes

 

[bolide]

The TB needs the cruise control ECU to set idle. So you're going to have to fit the cruise ECU or a different TB and different loom

Nick Froome

 

[hismajestics]

@bolide,

is it enough to connect the round multipin female cable by the throttle body and I can cut off cables to the cruise control arm and sensors for the pedals? I do not need the cruise.

/johannes

 

[hismajestics]

It works! Thanks again, bolide

Tomorrow I'll cut off the the cruise auxiliaries and check if they are needed at all.

 

[adibikus]

Can someone help me out. My W124 E280 M104 seems to be stuck at 1500 rpm...the CC/ISC ECU under the passenger carpet has gone kaput. How can I bypass the 1500 rpm limit without changing the ECU? I don't mind losing my cruise control. How do I remove the cruise control?

 

[hismajestics]

Can someone help me out. My W124 E280 M104 seems to be stuck at 1500 rpm...the CC/ISC ECU under the passenger carpet has gone kaput. How can I bypass the 1500 rpm limit without changing the ECU? I don't mind losing my cruise control. How do I remove the cruise control?

Replied to adibikus PM:

"Hi,

you need a new ECU. M104 idle is controlled by that specific ECU under the passenger seat and without it, the engine will not rev above 1500rpm. You can bypass it only by installing a standalone engine control unit. It is easier and cheaper for you to pick up a used CC/ISC from wreckers.

BR
johannes"