P1826

DTC P1826












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 that IMS Signal C is high while the vehicle is being driven in a forward gear, then DTC P1826 sets. DTC P1826 is a type C DTC.

Conditions for Running the DTC
^ The system voltage is 9 - 18 volts.
^ The engine speed is at least 500 RPM for 5 seconds and not in fuel shutoff.
^ No VSS DTCs P0502 or P0503.
^ Vehicle speed is greater than 14 km/h (10 mph).
^ Engine torque is greater than 27 Nm (20 ft. lbs.).
^ DTC P1826 has not passed this key cycle.

Conditions for Setting the DTC
The PCM detects IMS Signal C is high, while the gear ratio indicates first, second or third gear 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 P1826 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. This step tests the integrity of the engine harness and PCM by checking for the Signal C 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.