Yesterday my 2012 6,500 miles van failed its MoT. This is not, for me, a normal occurrence. I'd serviced it over the previous week (Merc B Service) so after a final check on lights I set off confident as ever. It failed because the 'engine' light failed to extinguish. The MoT man gave me 'that look' when I told him it performed as expected when I left home.
So I took my rather embarrassed van home. I have a code reader (nothing special - just a phone app & Bluetooth plug) not expecting much because the engine light can cover a multitude of problems and doesn't always present a helpful code. Anyway this time it did and the code was for Cylinder 5 heater plug failure. Even at that point it could still be other things like the controller or wiring. If you have ever seen the top of a Merc V6 you will understand that although there isn't an engine cover there is a mass of pipes and connectors and an air cleaner box, and the turbo, the turbo silencer, and all its piping. So several hours later and in agony from being bent double to work through the letterbox bonnet opening I was able to see the heater plug, remove its connector, and test it. It was faulty! I think this is the first time I've had such a precise result from any code reader.
I also discovered the reason why it hides until started by the MoT man. Before I did any work I reset the engine warning / code. At the first restart there was a very brief flash-up of the heater plugs symbol (which doesn't normally happen at this time of year). At the second restart the same happened again but the engine warning light stayed on. So it's on a counter - of two! I've come across numerous faults that are on counters but until now I haven't seen one (on a counter) that doesn't count to at least 6.
Anyway - plug is on order and I'm delighted it was all so easy and with a free re-test And, more importantly, not my fault
.
So I took my rather embarrassed van home. I have a code reader (nothing special - just a phone app & Bluetooth plug) not expecting much because the engine light can cover a multitude of problems and doesn't always present a helpful code. Anyway this time it did and the code was for Cylinder 5 heater plug failure. Even at that point it could still be other things like the controller or wiring. If you have ever seen the top of a Merc V6 you will understand that although there isn't an engine cover there is a mass of pipes and connectors and an air cleaner box, and the turbo, the turbo silencer, and all its piping. So several hours later and in agony from being bent double to work through the letterbox bonnet opening I was able to see the heater plug, remove its connector, and test it. It was faulty! I think this is the first time I've had such a precise result from any code reader.
I also discovered the reason why it hides until started by the MoT man. Before I did any work I reset the engine warning / code. At the first restart there was a very brief flash-up of the heater plugs symbol (which doesn't normally happen at this time of year). At the second restart the same happened again but the engine warning light stayed on. So it's on a counter - of two! I've come across numerous faults that are on counters but until now I haven't seen one (on a counter) that doesn't count to at least 6.
Anyway - plug is on order and I'm delighted it was all so easy and with a free re-test And, more importantly, not my fault
.
