GM Service Manual Online
For 1990-2009 cars only

DTC P1854 European and N American Emissions

Circuit Description

The shift solenoids are 2 identical, normally open electronic exhaust valves that control upshifts and downshifts in all forward gear ranges. These shift solenoids work together in a combination of ON and OFF sequences to control the line pressure and shift mechanisms, such as clutches and brakes.

Solenoid 2 controls the high or low of the line pressure, the flow to each clutch valve, by the operation type, ON/OFF. For example, if solenoid 2 is ON, the line pressure will be low, 599-799 kPa (87-116 psi). If solenoid 1 is OFF, the line pressure will be high, 1 599-1 799 kPa (232-261 psi). Solenoid 2 controls the oil flow to the clutch valve E or the lock-up clutch valve by the ON/OFF signal.

The transmission control module (TCM) monitors numerous inputs to determine the appropriate solenoid state combination and transaxle gear for the vehicle operating conditions.

Conditions for Setting the DTC

    • The solenoid wiring is shorted to power.
    • No DTCs P1853 or P1855 are set.

Action Taken When the DTC Sets

    • The malfunction indicator lamp (MIL) will illuminate.
    • The 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.

Conditions for Clearing the MIL/DTC

    • The MIL 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 P1854 sets, the possible cause of the fault could be solenoid 2.

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check - Automatic Transmission ?

--

Go to Step 2

Go to Diagnostic System Check - Automatic Transmission

2

  1. Install the scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. Select Actuating on the scan tool.
  4. Actuate solenoid 2 ON/OFF.

Does the solenoid 2 change ON/OFF?

--

Go to Diagnostic Aids

Go to Step 3

3

  1. Remove the oil pan.
  2. Disconnect the wiring connector of solenoid 2.
  3. Turn the ignition ON, with the engine OFF.
  4. Measure the voltage of the solenoid 2 wiring connector terminal 1.

Is the voltage within the specified value?

11-14 V

Go to Step 4

Go to Step 5

4

Repair the internal line, solenoid 2, for a short to power.

Did you complete the repair?

--

System OK

--

5

Replace the solenoid 2.

Did you complete the replacement?

--

Go to Step 6

--

6

Check if any DTCs are set.

Are there any DTCs displayed that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List/Type

System OK

DTC P1854 Non Europe or N American Emissions

Circuit Description

The shift solenoids are 2 identical, normally open electronic exhaust valves that control upshifts and downshifts in all forward gear ranges. These shift solenoids work together in a combination of ON and OFF sequences to control the line pressure and shift mechanisms, such as clutches and brakes.

Solenoid 2 controls the high or low of the line pressure, the flow to each clutch valve, by the operation type, ON/OFF. For example, if solenoid 2 is ON, the line pressure will be low, 599-799 kPa (87-116 psi). If solenoid 1 is OFF, the line pressure will be high, 1 599-1 799 kPa (232-261 psi). Solenoid 2 controls the oil flow to the clutch valve E or the lock-up clutch valve by the ON/OFF signal.

The transmission control module (TCM) monitors numerous inputs to determine the appropriate solenoid state combination and transaxle gear for the vehicle operating conditions.

Conditions for Setting the DTC

    • The solenoid wiring is shorted to power.
    • No DTCs P1853 or P1855 are set.

Action Taken When the DTC Sets

    • The Hold lamp will blink.
    • The 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.

Conditions for Clearing the Hold Lamp/DTC

    • The Hold 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 P1854 sets, the possible cause of the fault could be solenoid 2.

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check - Automatic Transmission ?

--

Go to Step 2

Go to Diagnostic System Check - Automatic Transmission

2

  1. Install the scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. Select Actuating on the scan tool.
  4. Actuate solenoid 2 ON/OFF.

Does the solenoid 2 change ON/OFF?

--

Go to Diagnostic Aids

Go to Step 3

3

  1. Remove the oil pan.
  2. Disconnect the wiring connector of solenoid 2.
  3. Turn the ignition ON, with the engine OFF.
  4. Measure the voltage of the solenoid 2 wiring connector terminal 1.

Is the voltage within the specified value?

11-14 V

Go to Step 4

Go to Step 5

4

Repair the internal line, solenoid 2, for a short to power.

Did you complete the repair?

--

System OK

--

5

Replace the solenoid 2.

Did you complete the replacement?

--

Go to Step 6

--

6

Check if any DTCs are set.

Are there any DTCs displayed that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List/Type

System OK