Hi all, clutching at straws and need help, my daughters 2011 c max diesel keyless keeps giving engine preheating when ignition turned on and car will not turn over. Have had key checked and new one made, but still the same. Tried fob directly in column, leave it and try later it may or may not turn over / start. It has just stopped whilsg driving and cut out. Its random when it will or will not start but appears to be when engine preheating mezsage on dashboard. Any advise i would be grateful,

Thanks

Hi,

It won't attempt to start while it's pre-heating the glowplugs in cold weather.  This is a feature of ~post-2010 diesels to reduce exhaust emissions.

Cutting out while driving is a fault though, we would need to see the fault codes stored from cut-out to diagnose that any further.

Thanks Tomsfocus

When the ignition is turned on the pre heating engine warnimg stays on. And at times if you turn ignition off and on the warnimg doesnt come on. Even when car not used. Warnings are intermitent. 

Seems all problems are interlinked

I will find out codes thank you

 

 

 

 

On 12/21/2025 at 4:19 PM, richard phillips said:

Hi all, clutching at straws and need help, my daughters 2011 c max diesel keyless keeps giving engine preheating when ignition turned on and car will not turn over. Have had key checked and new one made, but still the same. Tried fob directly in column, leave it and try later it may or may not turn over / start. It has just stopped whilsg driving and cut out. Its random when it will or will not start but appears to be when engine preheating mezsage on dashboard. Any advise i would be grateful,

Thanks

Sound similar to the crank shaft position sensor giving out. But like Tom said it better to have it read rather than is or is it not ?

I have the opposite, in that glow plug light rarely/never comes on meaning starting is sometimes difficult in a cold snap, so any answers here may help.
No fault codes, power and grounds and glow plug resistances all at 0.5 Ohms so OK.
Against my better judgement but as it was relatively cheap I've changed the module but it has made no difference so far.
It used to be far simpler with a simple relay but my investigation reveals that there is now likely a dedicated chip that receives signals from the ECU and switches each plug individually via MOSFETs using PWM and also reports any faults - not exactly straightforward!
My next step is to monitor coolant temperature and the glow plug parameters in Forscan to see if there's any pattern.