Range Selector Displays Incorrect Range
Range Selector Displays Incorrect Range
Circuit Description
The transmission internal mode switch (IMS) is a sliding contact switch attached to the selector detent inside the transmission side cover. The four inputs to the powertrain control module (PCM) indicate the position of the transmission range selector. The input voltage level at the PCM is high, B+, when the IMS is open and low when the switch is closed to ground. The four input parameters represented are Signals A, B, C and P, Parity. Refer to Transmission Internal Mode Switch Logic.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. HI values for all signals in all ranges indicates the ground circuit is OPEN.
3. With the 20-way connector disconnected, all signals should indicate HI.
5. If one circuit affects the other, this indicates a short between the two circuits.
11. This step tests the internal transmission harness. If no fault is found in the harness, the fault will be in the switch.
