www.jec.org.uk

can anyone inform me why my restricted performance lightor the yellow light comes on it is on constantly but goes of after about 20 mins engine running as normal is this anything to worry about or get chected out

All warnings are there to denote faults, some are false alarms, but you never know until the problem is diagnosed or goes away.......we always try the easy ones first ,.....take the battery lead off for ten minutes or give it a charge up then see if the warning is still there....if it is you need the specialised equipment to diagnose the problem.....Joe

rob1968,

Did you ever get to the bottom of this? I'm just interested as I had a fault which brought this light on - see my thread under "Cooling" about my temperature gauge.

Paul

Does the fault light only come on when the vehicle is cold?

If so, the ECU thinks that the engine is hot and hence uses the mapping for normal running, however the feedback from the sensors will not be correct due to the engine being cold so the system flags a fault. Once the engine is up to normal temperature the problem goes away as the sensors are then reporting within their expected parameters.

I would suspect the engine coolant temperature sensor which is located in the engine coolant duct in the top hose and has two wires going to it (blue with yellow stripe and black with green stripe). British Parts UK (located in Stevenage) sell the coolant temperature sensors for £6.99 (+VAT & P&P) so it is a cheap part to replace (I would suggest buying one and then comparing the resistance across the terminals when the engine is cold on both the one in the car (with the harness disconnected and ignition off) and the new sensor.

If is is not the ECTS then it would be probably be worth purchasing a OBDII fault code reader with CAN capabilities (these are now available quite cheaply on eBay) to be able to find the fault.

Regards,

David

Rob did the battery option work?...........if please put your findings in the forum ...re the performace light.......Joe