Range Selector Displays Incorrect Range

Range Selector Displays Incorrect Range

Steps 1-6:

Steps 7-14:

Steps 15-17:

Circuit Description
The transmission internal mode switch (IMS) is a sliding contact switch attached to the lower control valve body, within the transmission. The manual valve link assembly then connects the IMS to the manual valve. The four inputs to the PCM from the IMS indicate which position is selected by the transmission selector lever. This information is used for engine controls as well as determining the transmission shift patterns. The input voltage level at the PCM is high, ignition voltage, when the IMS is open and low when the switch is closed to ground. The state of each input is available for display on the scan tool. The four input parameters represented are Signal A, Signal B, Signal C and Signal P, Parity.

Diagnostic Aids
Refer to Transmission Internal Mode Switch Logic.

Test Description
The numbers refer to the step numbers on the diagnostic table.
3. This step tests the IMS for an open ground circuit.
5. This step tests for correct reference voltage from the PCM.