4T65-E Automatic Transaxle
DTC P1822
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 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.
If the PCM detects that IMS Signal B is always high, then DTC P1822 sets. DTC P1822 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P1822 Internal Mode Switch B Circuit High Voltage
Conditions for Running the DTC
* No MAP DTC P0107 or P0108.
* The engine speed is greater than 500 RPM for 5 seconds and not in fuel cut off.
* Engine torque is 55-407 N.m (40-300 lb ft).
Conditions for Setting the DTC
The IMS Signal B is continuously high this ignition cycle, and the following conditions occur:
* The IMS indicates PARK for 2 seconds, then;
* The IMS indicates transitional position D2-D1 for 60 seconds.
Action Taken When the DTC Sets
* The PCM does not illuminate the malfunction indicator lamp (MIL).
* The PCM commands maximum line pressure.
* The PCM freezes transmission adaptive functions.
* The PCM assumes D4 for shifting.
* The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Failure Records.
* The PCM stores DTC P1822 in PCM history.
Conditions for Clearing the DTC
* A scan tool can clear the DTC.
* The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
* The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.
Test Description
The number below refers to the step number on the diagnostic table.
3. This step tests the integrity of the engine harness and PCM by checking for the TR Signal B state change from HI to LOW. A LOW signal indicates the fault is either in the internal transmission harness or the switch. A HI signal indicates the fault is either in the engine harness or the PCM.
