Xj12 ECU 16cu Advice Needed

It’s a way to bypass and troubleshoot a broken CTS so you can start and drive the car.
But this tells the ECU that the engine is infinitely warm and cold starts will be very difficult.

[quote=“PhilShot, post:20, topic:427094, full:true”]
Hi, there was no reading at all with the fluke. I read here (below link) that if you unplug the wiring to the sensor and bridge the connection it will give the ecu a false reading. I did this and the car fired up.

Bridging the connector, like with a paper clip, Phil; the ECU reads ‘0’ resistance - which indicates a very hot engine.

With the engine actually cold, say 0C (32F), the required resistance is 5,9 Kohm. With the plug shorted (‘0’ ohms) the the fueling will be very lean - and the engine cannot start and idle normally.

Flooring the pedal will to some extent enrich fueling, and the cold engine may run with high throttle settings. Needless to say, you cannot drive the car in this situation, but with the engine hot, the engine will behave better…:slight_smile:

It’s a bit surprising you get no resistance reading on the fluke - but a ‘cold’ CTS will be in the high Kohm range. So the correct scale must be used - at 80C (176F) the CTS resistance should be 325 ohms.

Measuring the resistance at various temps is of course the proper test of the CTS. If the reading is ‘break’, infinite, the ECU will fuel ‘fat’ - a short will fuel ‘lean’ as said…

You could use a variable or an assortment of resistors - but suggest you do other work, then work on engine’s running when you get a working CTS.

xj6 85 Sov Europe (UK/NZ)