Load potentiometer

At the factory, a learning of the full-load position is carried out on vehicles (storing the voltage delivered by the potentiometer at full load). This value is used to set the load potentiometer after replacement. It is therefore essential, if the injection ECU is changed during the vehicle's life, to carry out this learning (G31*).

When the load potentiometer is replaced, it must be adjusted. Compare the voltage supplied by the potentiometer in full-load position with the stored value. The new potentiometer is correctly adjusted when both voltages are identical. This can be checked on the XR25 diagnostic tool. The G32* reading shows the voltage difference between the stored value and the value supplied by the potentiometer. The adjustment is correct if this value is 0 in the accelerator-fully-depressed position.

Do not replace the potentiometer and the ECU at the same time. If necessary, replace the potentiometer first, then the ECU.

LOAD POTENTIOMETER REPLACEMENT (to be performed by two people)

Disconnect the three terminals for the load potentiometer from the 10-way pump connector (see Methods, chapter 13 "Advance solenoid valve").

Remove the two screws securing the faulty potentiometer and take it out. Install the replacement potentiometer. Fit the two securing screws without tightening them (it must be possible to turn the potentiometer body).

Connect the XR25 diagnostic tool, then switch on the ignition.

Set the selector to S8.

Enter the code then

Fully depress the accelerator pedal (accelerator-fully-depressed position). Do not act directly on the load lever.

Holding the accelerator-fully-depressed position, turn the potentiometer body until the tool display reads 0. If the value is too far from 0, the display shows HL (Out of Limit). Turn the potentiometer body until a decimal value appears.

Tighten the two potentiometer securing screws in the accelerator-fully-depressed position when the reading is 0.