P1887

DIAGNOSTIC TROUBLE CODE (DTC) P1887 TCC RELEASE SWITCH CIRCUIT MALFUNCTION





Circuit Description
The Torque Converter Clutch (TCC) release switch is part of the Automatic Transmission Fluid Pressure Manual Valve Position Switch (TFP Val. Position Sw.) that is mounted to the transmission valve body. The switch is a normally closed switch. The purpose of the switch is to provide a signal to the Powertrain Control Module (PCM) that the TCC is released. This is accomplished by Torque Converter release fluid pressure acting on the switch contact and opening the circuit. When the voltage is high on circuit 512, the PCM recognizes that the TCC is no longer engaged.
When the PCM detects the TCC release switch is open indicating TCC is not applied and TCC slip speed indicate the TCC is engaged, then DTC P1887 sets.

Conditions For Setting The DTC
- No Input Speed Sensor DTCs P0716 or P0717.
- No TCC solenoid DTCs P0741 or P0742.
- Engine running.
- Transmission is in D4.
- TCC commanded On.
- TCC slip speed is between -20 rpm and 20 rpm.
- TCC release switch is open.
- All above conditions met for 10 seconds.

Action Taken When The DTC Is Set
- PCM will illuminate the Malfunction Indicator Lamp (MIL) after two consecutive trips with a failure reported.
- Freeze shift adapts from being updated.
- PCM inhibits TCC engagement.
- DTC P1887 will be stored in PCM memory.

Conditions For Clearing The DTC
- The PCM turns off the MIL after three consecutive ignition cycles without a failure reported.
- History DTCs can be cleared by using a Scan Tool.

Diagnostic Aids
- Inspect the wiring for poor electrical connections at the PCM and at the transmission 20-way connector.
Look for possible bent, backed out, deformed or damaged terminals. Check for weak terminal tension as well. Also check for chafed wires that could short to bare metal or other wiring. Inspect for broken wire inside the insulation.
- If diagnosing for a possible intermittent short or open condition, move or massage the wiring harness while observing test equipment for a change.

Test Description
The numbers below refer to the step numbers on the diagnostic chart.
5. This Step tests the PCM's ability to recognize an open circuit.
6. This Step tests the PCM's ability to recognize a grounded circuit.

DTC P1887 - TCC Release Switch Circuit Malfunction





Step 1 - 10





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