Ignition Circuit Monitoring Temp Sensor 89-95
The sensors are mounted at the cylinders 4 and 8 on '89 and '90 models, and at cylinders 3 and 7 on the '91- models.
Mounting the sensor srequires Molykote HTP paste (white) and torque should be 10Nm.
New sealing rings should be used, nr 013.812.6 refer to manual pages 28-75 to 29-78
Checking the voltage for proper operation:
1. start the engine and bring it to proper operation temperature
2. pivot the limp-mode relay and move it a bit up, not removing it, to get access to the pins.
3. set voltmeter to 10mv range and connect leadt to e2 and 1e
4. measure voltage at idling 2000 rpm. Voltage difference must remain withing range of -2,5 mv to +2,5mv. If the measurement exceeds range, loosen one sensor an d rotate, fasten and test again. If still out of range, do same on other sensor. If still out of range replace sensors.
This is not really a limp mode, but a design to prevent the car from catching fire. Driving the car in this limp mode will make it ruin badly, and it is known to cause serious vibrations that make the torque tube snap. Really.
IMR -> Green LED = Driver side problems, Red LED = Passengerside problems.