P1816

DTC P1816 (3.0L (L81))






Circuit Description

The automatic transmission fluid pressure (TFP) manual valve position switch consists of six pressure switches. Five of the switches are normally-open, and determine gear range selection. The sixth switch is normally-closed, and detects torque converter clutch (TCC) release fluid pressure. The TFP manual valve position switch also contains the automatic transmission fluid temperature (TFT) sensor. These components are combined into one unit, attached to the control valve body.

The TCM provides battery voltage on the three range signal circuits. By grounding one or more of the switches with fluid pressure from the manual shift valve, the TCM detects the selected gear range. When you disconnect the transmission electrical connector and the ignition is ON, the ground potential for three range signals from the TCM will be removed, and an invalid gear range will be indicated.

When the TCM detects P/N indicated with a drive gear ratio, DTC P1816 sets. DTC P1816 is a type B DTC.

Conditions for Running the DTC

- No TP DTCs P0121, P0122, or P0123.
- No VSS DTCs P0502 or P0503.
- No AT ISS DTCs P0716 or P0717.
- No shift solenoid performance DTCs P0751, P0752, P0756, or P0757.
- No shift solenoid electrical DTCs P1842, P1843, P1845, or P1847.
- No PSA DTCs P1810 or P1815.
- The engine run time is greater than 5 seconds.
- The TPS is greater than 10 percent.
- The engine torque is greater than 35 Nm (26 lb ft).

Conditions for Setting the DTC

The TCM detects P/N with a drive ratio less than 0.72 for 5 seconds.

Action Taken When the DTC Sets

- The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
- The TCM elevates line pressure.
- The TCM assumes a D4 shift pattern.
- The TCM freezes transmission adaptive functions.
- The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
- The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
- The TCM stores DTC P1816 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC

- The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
- A scan tool can clear the MIL/DTC.
- The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
- The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

3. This step tests the indicated range signal to the manual valve range actually selected.
6. This step tests for correct voltage from the TCM.