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For 1990-2009 cars only

DTC P1841 Non-Europe or N. American Emissions

Circuit Description

The pressure control valves (PCS) valves 3, 4, 5, and 6 are precision electronic pressure regulators that control the operation of the clutches, brakes and lock-up clutch.

The valve reduces the system pressure with which the downstream solenoid valves and the electrical pressure regulating valves are supplied. As a result, smaller solenoid valves may be used. The PCS requires a constant input pressure.

Conditions for Setting the DTC

    • Output voltage of the PCS 3 is less than 10 mA.
    • No DTC P1839, P1840.
    • Immediately after the above condition occurs

Action Taken When the DTC Sets

    • The hold lamp will blink.
    • The transmission control module (TCM) will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.
    • Adopt Emergency/Substitute mode and constant 4th gear by hydraulic control.
    • After ignition OFF/ON: 3rd gear by hydraulic control. P, R, and N also possible.
    • Power supply cut off to the PCS valve.

Conditions for Clearing the Hold Lamp/DTC

    • The hold lamp will turn OFF when the malfunction has not occurred after 3 ignition cycles.
    • A history DTC will clear after 40 consecutive warm-up cycles without a fault.
    • Using a scan tool can clear history DTCs.

Diagnostic Aids

When DTC P1841 sets, the possible cause of the fault could be the PCS 3 valve.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install the scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. Select Actuating on the scan tool.
  4. Actuate the pressure control valves (PCS) 3 ON/OFF.

Does the PCS 3 change ON/OFF?

--

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn the ignition OFF.
  2. Disconnect the transaxle wiring connector.
  3. Measure the resistance between terminals 5 and 6 of the transaxle wiring connector.

Is the resistance within the specified value?

TFT 25°C (77°F)

6 ohms

Go to Step 7

Go to Step 4

4

  1. Remove the oil pan.
  2. Disconnect the wiring connector of the PCS 3.
  3. Measure the resistance between terminal 2 of the PCS 3 and terminal 5 of the transaxle connector.
  4. Measure the resistance between terminal 1 of the PCS 3 and terminal 6 of the transaxle connector.

Is the resistance approximately equal to the specified value?

0 ohms

Go to Step 6

Go to Step 5

5

  1. Repair the circuit between terminal 2 and terminal 5 for an open.
  2. Repair the circuit between terminal 1 and terminal 6 for an open.

Is the repair complete?

--

System OK

--

6

Replace the PCS 3.

Is the replacement complete?

--

System OK

--

7

  1. Disconnect the transaxle wiring connector and the transmission control module (TCM) connector.
  2. Measure the resistance between terminal 5 of the transaxle wiring connector and terminal C7 of the TCM wiring connector.
  3. Measure the resistance between terminal 6 of the transaxle wiring connector and terminal A11 of the TCM wiring connector.

Is the resistance approximately equal to the specified value?

0 ohms

Go to Step 9

Go to Step 8

8

Repair the transaxle wiring harness for an open.

Is the repair complete?

--

System OK

--

9

Replace the TCM. Refer to Transmission Control Module Replacement .

Is the replacement complete?

--

Go to Step 10

--

10

  1. After the repair, use a scan tool Clear Info function.
  2. Road test the vehicle.
  3. Review the DTC info.

Has the last test failed or is the current DTC displayed?

--

Go to Step 2

System OK

DTC P1841 European and N. American Emissions

Circuit Description

The pressure control valves (PCS) valves 3, 4, 5, and 6 are precision electronic pressure regulators that control the operation of the clutches, brakes, and lock-up clutch.

The valve reduces the system pressure with which the downstream solenoid valves and the electrical pressure regulating valves are supplied. As a result, smaller solenoid valves may be used. The PCS requires a constant input pressure.

Conditions for Setting the DTC

    • Output voltage of the PCS 3 is less than 10 mA.
    • No DTC P1839, P1840.
    • Immediately after the above condition occurs

Action Taken When the DTC Sets

    • The malfunction indicator lamp (MIL) will illuminate.
    • The transmission control module (TCM) will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.
    • Adopt Emergency/Substitute mode and constant 4th gear by hydraulic control.
    • After ignition OFF/ON: 3rd gear by hydraulic control. P, R, and N also possible.
    • Power supply cut off to the PCS valve.

Conditions for Clearing the MIL/DTC

    • The MIL will turn OFF when the malfunction has not occurred after 3 ignition cycles.
    • A history DTC will clear after 40 consecutive warm-up cycles without a fault.
    • Using a scan tool can clear history DTCs.

Diagnostic Aids

When DTC P1841 sets, the possible cause of the fault could be the PCS 3 valve.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install the scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. Select Actuating on the scan tool.
  4. Actuate the pressure control valves (PCS) 3 ON/OFF.

Does the PCS 3 change ON/OFF?

--

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn the ignition OFF.
  2. Disconnect the transaxle wiring connector.
  3. Measure the resistance between terminals 5 and 6 of the transaxle wiring connector.

Is the resistance within the specified value?

TFT 25°C (77°F)

6 ohms

Go to Step 7

Go to Step 4

4

  1. Remove the oil pan.
  2. Disconnect the wiring connector of the PCS 3.
  3. Measure the resistance between terminal 2 of the PCS 3 and terminal 5 of the transaxle connector.
  4. Measure the resistance between terminal 1 of the PCS 3 and terminal 6 of the transaxle connector.

Is the resistance approximately equal to the specified value?

0 ohms

Go to Step 6

Go to Step 5

5

  1. Repair the circuit between terminal 2 and terminal 5 for an open.
  2. Repair the circuit between terminal 1 and terminal 6 for an open.

Is the repair complete?

--

System OK

--

6

Replace the PCS 3.

Is the replacement complete?

--

System OK

--

7

  1. Disconnect the transaxle wiring connector and the transmission control module (TCM) connector.
  2. Measure the resistance between terminal 5 of the transaxle wiring connector and terminal C7 of the TCM wiring connector.
  3. Measure the resistance between terminal 6 of the transaxle wiring connector and terminal A11 of the TCM wiring connector.

Is the resistance approximately equal to the specified value?

0 ohms

Go to Step 9

Go to Step 8

8

Repair the transaxle wiring harness for an open.

Is the repair complete?

--

System OK

--

9

Replace the TCM. Refer to Transmission Control Module Replacement .

Is the replacement complete?

--

Go to Step 10

--

10

  1. After the repair, use a scan tool Clear Info function.
  2. Road test the vehicle.
  3. Review the DTC info.

Has the last test failed or is the current DTC displayed?

--

Go to Step 2

System OK