For 1990-2009 cars

## DTC P1839 Non-European or N. American Emissions

### Circuit Description

The pressure control solenoid (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 2 volts.

• | DTCs P1840 and P1841 are not present

• | 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 P1839 sets, the possible cause of the fault could be the PCS 3 valve.

#### DTC P1839

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 solenoid (PCS) valve 3 ON/OFF.
5. Observe the input speed on the scan tool.

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 ground.
4. Measure the resistance between terminal 1 of the PCS 3 and ground.

Is the resistance within the specified value?

∞

Go to Step 6

Go to Step 5

5 | Repair the internal line PCS 3 for a short to ground. 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 PCS 3 and ground.
3. Measure the resistance between terminal 6 of the PCS 3 and ground.

Is the resistance at the specified value?

∞

Go to Step 9

Go to Step 8

8 | Repair the transaxle wiring harness for a short to ground. 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 P1839 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 2 volts.

• | No DTC P1840, P1841.

• | 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 P1839 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 ground.
4. Measure the resistance between terminal 1 of the PCS 3 and ground.

Is the resistance within the specified value?

∞

Go to Step 6

Go to Step 5

5 | Repair the internal line PCS 3 for a short to ground. 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 PCS 3 and ground.
3. Measure the resistance between terminal 6 of the PCS 3 and ground.

Is the resistance at the specified value?

∞

Go to Step 9

Go to Step 8

8 | Repair the transaxle wiring harness for a short to ground. 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