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Cruise control drops out and goes into limp mode
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Rosb   
Fri May 16 2025, 09:13pm
Joined: Jul 24 2021
Member No: #4784
Location: Torquay
 Hi folks. My 2006 2.7 car will drop into limp mode when the cruise is set and will suddenly drop out or even when it’s not set it will go into limp mode. It happens when the cruise is set or not set and can’t be set when in limp mode. From what I have read, the brake switch and loom can be the culprit.

I have changed, but the problem continues. I can travel anywhere from 20 to 50 kilometres before it happens, but it will always happen. I park the car and overnight it resets and will be fine the next morning until I drive it again. Does anyone have any ideas what might be the cause?
Regards John
Hattershaun   
Sat May 17 2025, 05:57am

Joined: Dec 19 2010
Member No: #320
Location: Bedfordshire, UK
 The engine ECU won’t allow cruise control to function if it detects a problem that puts the engine in ‘limp’ mode.

You’ll see three horizontal dashes ( - - - ) flashing instead of the cruise control speed in the top left-hand corner of the speedo display.

The cruise control system is OK; once you’ve fixed the fault causing the limp mode, cruise control will work again.

Limp mode could be caused by many factors, diagnostics will be needed to trace the fault.

On a 2.2HDi C6, I previously owned, a faulty vacuum solenoid that controlled turboboost pressure caused limp mode & non-functioning cruise control.
MGmike   
Sat May 17 2025, 08:34pm

Joined: May 21 2017
Member No: #3151
Location: South Queensferry
 Now now Shaun, don't confuse a 2.2 with a 2.7

But you are correct that a code read is the way forward

I find most limp mode faults are down to boost issues. The most common being a turbo actuator or the easy one, a MAP senor.

I'm sure there are more but I haven't encountered them "yet"
 

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