P1887

Circuit Description
The torque converter clutch (TCC) release switch is part of the automatic transmission fluid pressure (TFP) manual valve position switch. The TFP manual valve position switch is mounted to the transmission valve body. The switch is normally-closed.
The switch signals the PCM that the TCC is released. This is accomplished by torque converter release fluid pressure acting on the switch contact, thus opening the switch. When the voltage is high on the circuit, the PCM recognizes that the TCC is no longer engaged.
When the PCM determines that the TCC release switch is open (indicating that the TCC is not applied) and the TCC slip speed indicates that the TCC is applied, then DTC P1887 sets. DTC P1887 is a type B DTC.

Conditions for Running the DTC
^ No A/T ISS DTCs P0716 or P0717
^ No TCC DTCs P0741 or P0742
^ The engine is running.
^ The TFP manual valve position switch indicates D4 range.
^ The TCC is commanded ON.
^ The TCC slip speed is -20 to +40 RPM.
^ Engine torque is greater than 45 N.m (33 lb ft).

Conditions for Setting the DTC
TCC release pressure is present for 6 seconds, twice during the same trip.

Action Taken When the DTC Sets
^ The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
^ The PCM inhibits TCC engagement.
^ The PCM freezes shift adapts from being updated.
^ The PCM stores DTC P1887 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC
^ The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
^ A scan tool clears the DTC from PCM history.
^ The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
^ Inspect the wiring at the PCM, the transmission 20-way connector and the TFP manual valve position switch 6-way connector for the following conditions:
- A backed out terminal.
- A damaged terminal.
- Reduced terminal tension.
- A chafed wire.
- A broken wire inside the insulation.
- Moisture intrusion.
- Corrosion.
^ When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
4. This step tests the PCMs ability to recognize an open circuit.
5. This step tests the PCMs ability to recognize a grounded circuit.