Cruis control quit working

Z

ZetaTre

Active member
 San Diego County
Yesterday I installed the steering wheel control in the wife's Z4. While I was looking for the proper plug, I end up disconnecting the connector on the cruise control. I put it back and didn't think too much about it.

Today we were cruising down the freeway and the cruise control doesn't engages anymore. I checked the wiring and it's plugged in fine, check the fuse and it's ok. The battery has always been disconnected while I was installing the steering wheel control.

Any idea whether or not the cruise control requires to be coded and wether unplugging it requires recoding? Thanks
 
definitely requires coding, just had mine retrofitted.

not sure whether running the car without it confuses it into thinking it's not there..

EDIT: I know that's not true on a normal Zed, not sure why i posted it.
 
Several have been fitted by guys in the UK including me and never heard of any of them needed recoding. Battery disconnection doas not have any effect.

If all the steering wheel controls function correctly I'd suggest you did not reconnect the cruise control correctly or broke a wire, bent a pin in th econnector, etc. If that's all perfect disconnect the steering wheel loom and see it works again
 
No coding required, and the 2003 was the easiest model to fit to as the wiring was all there.
 
M is indeed different. Officially, it can not even be retrofitted at all whilst it can on "normal" Z4s.
 
I checked the small plug last night, the one underneat the steering column that plugs into the cruise control lever and it fine: no pins are bent or anything.

Installing the radio control requires also unplugging the connector behind the instrument cluster and the one behind the light switch control: does any of these two relate to the cruise control?

Everything else works perfectly fine... Well as far as I can tell it does. The brake and clutch switches also work fine (the car won't start is the clutch is not pressed in and the brake lights work fine).

Since this is a 01-2003 production so some additional wiring was required since cars before 09-2003 are only partially wired: it's required to tap into two wires by the light switch harness. The retrofit kit comes with everything and we followed the instruction steop by step.
 
Just a thought, if all connectors that were unpluged have been checked for bent pins, I would cut the wires added, one at a time and then check if cruise control starts working. I would cut wires added until the cruise starts working and that should point to where the issue is. IMHO
 
Ok, so I did some more homework as opposed to go Rambo style and take the steering apart again. I got my hands on a copy of the WDS (wiring diagram system) and I found out a couple of things.

The plug on the cruise control is X72 (which I unplugged by mistake instead of plug X10170 that was required by the steering wheel radio control retrofit)

GREO_E85_61_0001.png


The cruise control uses 3 pins #1, #2 and #4 (#3 is empty)

NewPicture.jpg


- pin #1 goes to the power distribution behind the glovebox and from there to fune #28 (which I checked for continuity and it's intact)

GREO_E85_61_0008.png


- pin #2 goes to the DME

GREO_E85_12_0020.png


- and pin #4 is the ground

GREO_E85_61_0023.png


This mean the problem is not related to the installation of the radio control: neither of these plugs is something I touched.

Based on the WDS, "faults detected in the cruise-control system are stored in the fault memory of the engine control module. These fault memory entries prevent any activation of the cruise-control system", however it doesn't specify whether any of these codes would triger the EML or CEL light.

Would anybody happens to know if a regular code reader could detect such codes, if any, or if the GT1 is required? I'm thinking the lever is tosted, but wanted to make sure, before buying another one...
 
I've seen warnings stored before on mine without raising the Check Engine light, so you might be lucky?

Interesting pics though.. It surely couldn't be that hard to retrofit in an /M using those diagrams. I had mine done recently and it was a 2hr job apparently, much of that must of been trim.
 
You must log in or register to reply here.
Back
Top Bottom