Note: This test is performed on the vehicle.
Connect the tester (in ohmmeter mode) to the benefits of "A" and "S" potentiometer.
Fully extend the throttle servo of the 1st chamber (in this case, the throttle valve is in the position corresponding to the engine braking mode) and measure the nominal sliding resistance, which should be within 0-250 ohms for 1983-1985 model year vehicles and at least 250 ohms for 1986 and later model year vehicles.
Slowly open the throttle valve to the position corresponding to full engine load, measuring the sliding resistance, which should gradually increase to a maximum value of 1.3-2.5 kOhm.
If the sliding resistance is not within the specified limits, replace the 1st chamber throttle potentiometer.