P1819

DTC P1819















Circuit Description with 4T65-E Automatic Transaxle
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 a combination of IMS signals that are invalid, or a transitional state (between gear selector positions), while attempting to start the vehicle, then DTC P1819 sets. DTC P1819is a type C DTC.

Conditions for Running the DTC
^ The system voltage is 9-18 volts.
^ The ignition switch is in the START position.

Conditions for Setting the DTC
The PCM detects a combination of IMS signals that are invalid or indicate a transitional state (between gear selector positions) for 0.5 seconds.

Action Taken When the DTC Sets
^ The PCM does not illuminate the malfunction indicator lamp (MIL).
^ 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 P1819 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 numbers below refer to the step numbers on the diagnostic table.
3. Hi values for all signals in both PARK and D4 ranges indicates the ground circuit is OPEN.
5. With the 20-way connector disconnected, all signal circuits are open. All signals should indicated HI.
7. If one circuit affects the other, this indicates a short between the two circuits.
13. This step tests the internal transmission harness. If no fault is found in the harness, the fault will be in the switch.