4L80-E (MT1) Transmission

Transmission Range (TR) Pressure Switch Assembly Circuit Check:

Transmission Range (TR) Pressure Switch Assembly Circuit Check:

Transmission Range (TR) Signal:

CIRCUIT DESCRIPTION
The Transmission Range (TR) switch assembly consists of five normally open pressure switches and is attached to the valve body. The Powertrain Control Module (PCM) supplies battery voltage to each range signal. By grounding one or more of these circuits through various combinations of the pressure switches, the PCM detects what manual valve position has been selected by the vehicle operator. With ignition "ON" and engine "OFF," P/N will be indicated. When transmission electrical connector is disconnected, the ground potential for the three range signals to the PCM will be removed, and with ignition "ON," D2 will be indicated.

DIAGNOSTIC TROUBLE CODE (DTC) CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic charts.

1. This test checks the indicated range signal to the manual valve position actually selected.
2. This test checks for correct Voltage from the PCM to the transmission external connector.
3. This test checks for a short to ground from the PCM to the-transmission external connector in any one of the three circuits.

DIAGNOSTIC AIDS
Refer to accompanying chart for various A/B/C range combinations. Check all wiring connectors for proper terminal tension.

Refer to Automatic Transmission for further information.