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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1995 🢒 Cavalier 🢒 Transmission/Transaxle 🢒 Automatic Transaxle - 4T40-E 🢒 DTC P1887 TCC Release Switch Circuit

Object Number: 40584 Size: MF
Automatic Transmission Components
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

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.). The TFP Val. Position Sw. is mounted to the transmission valve body. The switch is normally-closed.

The switch signals the Powertrain Control Module (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 Powertrain Control Module 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 A DTC.

Conditions for Setting the DTC
    • No TCC Solenoid DTCs P0741 or P0742
    • No Input Speed Sensor DTCs P0716 or P0717
    • The engine is running.
    • The TFP Val. Position Sw. indicates D4 range.
    • The TCC is commanded ON.
    • The TCC slip speed is -20 to +20 RPM.
    • The TCC release switch is open.
    • All of the above conditions are met for 10 seconds.

Action Taken When the DTC Sets
    • The PCM illuminates the Malfunction Indicator Lamp (MIL).
    • The PCM freezes shift adapts from being updated.
    • The PCM inhibits TCC engagement.
    • DTC P1887 is stored in the PCM history.

Conditions for Clearing the MIL/DTC
    • The PCM turns OFF the MIL after three consecutive ignition cycles without a failure reported.
    • A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.
    • The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

Diagnostic Aids
    • Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections at the transmission 20-way connector. Look for the following conditions:
       - A bent terminal
       - A backed out terminal
       - A damaged terminal
       - Poor terminal tension
       - A chafed wire
       - A broken wire inside the insulation
    • 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.

  1. This Step tests the PCM's ability to recognize an open circuit.

  2. This Step tests the PCM's ability to recognize a grounded circuit.

P1887

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to

Powertrain On Board Diagnostic (OBD) System Check in Engine Controls - 2.3L

2
  1. Install the scan tool (tech 1) .
  2. With the engine OFF, turn the ignition switch to the RUN position.

    3. Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data.

  3. Record the DTC Freeze Frame and Failure Records.
  4. Select scan tool TCC Release Switch.

Is the TCC Release Switch status as specified?

Closed

Go to Step 3

Go to Step 5

3

Start the engine.

Is the TCC Release Switch status as specified?

Open

Go to Step 14

Go to Step 4

4

  1. Turn the ignition OFF.
  2. Disconnect the Automatic Transmission 20-way connector (additional DTCs will set).
  3. With the engine OFF, turn the ignition switch to the RUN position.

Is the TCC Release Switch status as specified?

Open

Go to Step 8

Go to Step 7

5

  1. Install the J 39775 Jumper Harness to the engine 20-way connector.
  2. Using the J 35616-A Connector Test Adapter Kit, connect a fused jumper from terminal U to a good ground.

Is the TCC Release Switch status as specified?

Closed

Go to Step 8

Go to Step 6

6

Inspect circuit 657 for an open.

Refer to Troubleshooting Procedures, Section 8.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 13

7

Inspect circuit 657 for a short to ground.

Refer to Troubleshooting Procedures, Section 8.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 13

8
  1. Disconnect the J 39775 Jumper Harness from the engine 20-way connector.
  2. Install the J 39775 Jumper Harness to the Automatic Transmission 20-way connector.
  3. Using the J 35616-A Connector Test Adapter Kit, connect an ohmmeter from terminal U to a good ground.

Is the resistance less than the specified value?

50ohms

Go to Step 9

Go to Step 10

9

Start the engine.

Is the resistance greater than the specified value?

50ohms

Go to Step 10

Go to Step 11

10

Inspect circuit 1804 for an open.

Refer to Troubleshooting Procedures, Section 8.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

11

Inspect circuit 1804 for a short to ground.

Refer to Troubleshooting Procedures, Section 8.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

12

Replace the TFP Val. Position Sw.

Refer to Automatic Transmission Fluid Pressure Manual Valve Position Switch Replacement, in On-Vehicle Service.

Is the replacement complete?

--

Go to Step 15

--

13

Replace the PCM.

Refer to Section 6:

Powertrain Control Module/EEPROM Replacement/Programming in Engine Controls - 2.3L

Is the replacement complete?

--

Go to Step 15

--

14

Inspect for the following conditions:

    • Leaking torque converter o-ring seal (41) - Refer to Case and Associated Parts, in Transmission Component Location .
    • Cut torque converter o-ring seal (41).
    • Debris or flash blocking the channel plate (27) (Refer to Case and Associated Parts, in Transmission Component Location ) at the TCC release exhaust passage (48) - Refer to Channel Plate Passages, in Transmission Component Location .
    • Leaking oil pump bearing and seal assembly (200) seal - Refer to Oil Pump Assembly, in Transmission Component Location .
    • Cut oil pump bearing and seal assembly (200) seal.
    • Oil pump bearing and seal assembly (200) installed backwards.
    • Misaligned valve body to spacer plate gasket (22) - Refer to Case and Associated Parts, in Transmission Component Location .
    • Misaligned spacer plate to channel plate gasket (24).
    • Channel plate (27) turbine shaft sleeve installed backwards, or with no press fit.
    • Valve body spacer plate (23) (Refer to Case and Associated Parts, in Transmission Component Location ) release exhaust orifice (46) (Refer to Channel Plate Passages, in Transmission Component Location ) blocked by debris, valve body to spacer plate gasket (22), or spacer plate to channel plate gasket (24).
    • Cut turbine shaft to sprocket seal (33) - Refer to Case and Associated Parts, in Transmission Component Location .
    • Missing turbine shaft to sprocket seal (33).

Refer to Unit Repair

Did you find and correct the condition?

--

Go to Step 15

--

15

In order to verify your repair, perform the following procedure:

  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle under the following conditions:
    4. • Drive the vehicle in D4 in order to obtain 74 km/h (45 mph).
    • With the TCC commanded ON and engaged, the TCC release switch status must be Closed (no release oil present at the switch) for 3 seconds.
  4. Select Specific DTC. Enter DTC P1887.

Has the test run and passed?

--

System OK

Begin the diagnosis again. Go to Step 1