Hi All 👋

 

I'm new here and hoping someone might might also be to help with an issue I've been having with VRS! 

 

I've got a 2016 petrol VRS which I've owned for around 2 and half years and I bloody love it! I've done nearly 65,000 miles in that time (on 94k now) and it's never put a foot wrong or failed to carry on being able to put a smile on my face. 

 

Recently it's thrown up a P268100 fault code, "engine coolant bypass valve control circuit open". On a recent service at the dealer they also picked up on a small coolant leak from the waterpump housing. I did a small amount of research and put 2 and 2 together and thought this was the issue and spent all yesterday afternoon replacing the water pump and the housing, however after clearing the codes it's came straight back up again much to my disappointment. 

 

Has anybody else had a simular problem or can point me in the right direction before I send it into a garage for diagnosis work? 

 

Many thanks 

 

Chris 😊

The coolant bypass valve is located on the opposite end to the timing end. It is just above the gearbox bell housing, small black cylinder with an electrical plug and 2 coolant pipes.

 

Fairly common for failing 

P268100 bypass valve is the thermal management control unit. I.e. electronic thermostatat. Had me questioning whether it was the solenoid stop valve with the description given in fault code (when the thermostat failed on me)  but I can assure you it is. Unplug the solenoid valve and observe the desscriptor if you have cause to doubt. 

 

Your scenario also happened to me. Cct open means the ecu thinks it is not connected.  And I was left with several possibilities 1. Ecu output to tcmu fried, 2. Wiring from ecu to tmcu plug 3. New tmcu faulty out of box.

 

What it turned out to be in my case after partially disassembling the work again and then  removing connector plug to tmcu is the o ring inside the plug had got rolled and had stopped the connector engaging properly even though I had pushed the grey tab down. That grey lock tab doesn't guarantee the connector has engaged properly! 

Edited 16 October, 20232 yr by TheClient

Hi Guys 

 

Thank you for your replies, really helpful! I Will have a look this afternoon and see how I get on.