For 1990-2009 cars

## DTC P0785 3-2 Shift Solenoid Circuit Electrical 5.7L

Automatic Transmission Components VIN G
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The 3-2 Shift Solenoid Valve Assembly (3-2 SS Valve Assy.) is a normally-closed, 3-port, on/off device that controls the 3-2 downshift. The solenoid attaches to the control valve body within the transmission. The solenoid receives ignition voltage through circuit 239. The Powertrain Control Module (PCM) controls the solenoid by providing a ground path on circuit 687. During a 3-2 downshift, the 2-4 band applies as the 3-4 clutch releases. The PCM varies the timing between the 3-4 clutch release and the 2-4 band apply depending on the vehicle speed and the throttle position.

When the PCM detects a continuous open or short to ground in the 3-2 SS Valve Assy. circuit or the 3-2 SS Valve Assy., then DTC P0785 sets. DTC P0785 is a type A DTC.

### Conditions for Setting the DTC

• | The system voltage is 8-16 volts.

• | The engine speed is greater than 450 RPM for 5 seconds.

• | Not in fuel cutoff.

• | All of the above conditions are met for 5 seconds and either of the following fail conditions occurs for 5 seconds:

- | The PCM commands the solenoid ON and the voltage input remains high (B+).

- | The PCM commands the solenoid OFF and the voltage input remains low (0 volts).

### Action Taken When the DTC Sets

• | The PCM illuminates the Malfunction Indicator Lamp (MIL).

• | The PCM commands a soft landing to third gear.

• | The PCM commands maximum line pressure.

• | The PCM inhibits TCC engagement.

• | The PCM inhibits fourth gear if the transmission is in hot mode.

• | The PCM freezes shift adapts from being updated.

• | DTC P0785 stores in the PCM history.

### Conditions for Clearing the MIL/DTC

• | The PCM turns OFF the MIL after three consecutive trips 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 at the PCM, the transmission connector and all other circuit connecting points 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

- | Moisture intrusion

- | Corrosion

• | 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 ability of the PCM to control the solenoid.

2. This step tests for power to the 3-2 SS Valve Assembly.

3. This step tests the ability of the PCM and wiring to control the ground circuit.

4. This step tests the resistance of the Automatic Transmission Wiring Harness Assembly (A/T Wiring Harness Assembly) and the 3-2 SS Valve Assembly.

#### DTC P0785 3-2 Shift Solenoid Circuit - Electrical (5.7L, VIN G)

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 |

1. Install the Scan Tool .
2. With the engine OFF, turn the ignition switch to the RUN position.

Important:: Before clearing the DTC(s), use the scan tool in order to record the Freeze Frame and Failure Records for reference. Using the Clear Info function will erase the stored Freeze Frame and Failure Records from the PCM.

3. Record the DTC Freeze Frame and Failure Records, then clear the DTC(s).

Are DTCs P0740, P0753, P0758, and P1860 also set?

--

Go to Step 3

Go to Step 4

3 |

1. Inspect the ENG CTRL fuse.
2. If the fuse is open, inspect circuit 239 (PNK), the solenoids, and the A/T Wiring Harness Assembly for a short to ground. Repair the circuit, the solenoids, and the harness if necessary.

Refer to General Electrical Diagnosis in Wiring Systems.

Did you find and correct a short to ground condition?

--

Go to Step 16

Go to Step 5

4 | Using the transmission output control function on the scan tool, command the 3-2 SS Valve Assembly ON and OFF three times, while listening to the bottom of the transmission pan (a stethoscope may be necessary). Does the solenoid click when commanded? | -- | Go to Diagnostic Aids | Go to Step 5
5 |

1. Turn the ignition OFF.
2. Disconnect the transmission 20-way connector (additional DTCs will be set).
3. Install the J 39775 Jumper Harness on the engine side of the 20-way connector.
4. With the engine OFF, turn the ignition switch to the RUN position.
5. Connect a test lamp from J 39775 Jumper Harness cavity E to ground.

Is the test lamp ON?

--

Go to Step 7

Go to Step 6

6 | Repair the open or short to ground in ignition feed circuit 239 (PNK) to the 3-2 SS Valve Assembly. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 16 | --
7 |

1. Install a test lamp from cavity E to cavity S of the J 39775 Jumper Harness.
2. Using the transmission output control function on the scan tool, command the 3-2 SS Valve Assembly ON and OFF three times.

Is the test lamp ON when the solenoid is commanded ON, and OFF when the solenoid is commanded OFF?

--

Go to Step 9

Go to Step 8

8 |

1. Inspect circuit 687 (WHT) of the engine wiring harness for an open, short to ground or short to power condition.

Refer to General Electrical Diagnosis in Wiring Systems.

2. Repair the circuit if necessary.

Refer to Wiring Repairs in Wiring Systems.

Did you find an open, short to ground or short to power condition?

--

Go to Step 16

Go to Step 10

9 |

1. Install the J 39775 Jumper Harness on the transmission side of the 20-way connector.
2. Using the J 39200 Digital Multimeter (DMM) and the J 35616-A Connector Test Adapter Kit, measure the resistance between terminal E and terminal S.

Is the resistance within the specified range?

20-32 ohms

Go to Step 12

Go to Step 11

10 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Is the replacement complete? | -- | Go to Step 16 | --
11 |

1. Disconnect the A/T Wiring Harness Assembly from the 3-2 SS Valve Assembly.
2. Measure the resistance of the 3-2 SS Valve Assembly.

Is the resistance within the specified range?

20-32 ohms

Go to Step 14

Go to Step 15

12 | Measure the resistance between terminal S and ground, and between terminal E and ground. Are both measurements greater than the specified value? | 250 K ohms | Go to Diagnostic Aids | Go to Step 13
13 |

1. Disconnect the A/T Wiring Harness Assembly from the 3-2 SS Valve Assembly.
2. Measure the resistance from the component's terminals to ground.

Are both measurements greater than the specified value?

250 K ohms

Go to Step 14

Go to Step 15

14 | Replace the A/T Wiring Harness Assembly. Refer to Torque Converter Clutch Pulse Width Modulation Solenoid, Torque Converter Clutch Solenoid, and Wiring Harness Replacement. Is the replacement complete? | -- | Go to Step 16 | --
15 | Replace the 3-2 SS Valve Assembly. Refer to Control and Shift Solenoids Replacement . Is the replacement complete? | -- | Go to Step 16 | --
16 | In order to verify your repair, perform the following procedure:

1. Select DTC.
2. Select Clear Info.
3. Drive the vehicle in D3 or D4 and perform a 3-2 downshift. Ensure the following conditions are met:

• | The PCM commands the 3-2 SS Valve Assembly ON and the voltage input drops to zero.

• | The PCM commands the 3-2 SS Valve Assembly OFF and the voltage input increases to B+.

• | All conditions are met for 5 seconds.

4. Select Specific DTC. Enter DTC P0785.

Has the test run and passed?

--

System OK

Go to Step 1

## DTC P0785 3-2 Shift Solenoid Circuit Electrical 3.8L

Automatic Transmission Components VIN K
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The 3-2 Shift Solenoid Valve Assembly (3-2 SS Valve Assy.) is a normally-closed, 3-port, on/off device that controls the 3-2 downshift. The solenoid attaches to the control valve body within the transmission. The solenoid receives ignition voltage through circuit 239. The Powertrain Control Module (PCM) controls the solenoid by providing a ground path on circuit 687. During a 3-2 downshift, the 2-4 band applies as the 3-4 clutch releases. The PCM varies the timing between the 3-4 clutch release and the 2-4 band apply depending on the vehicle speed and the throttle position.

When the PCM detects a continuous open or short to ground in the 3-2 SS Valve Assy. circuit or the 3-2 SS Valve Assy., then DTC P0785 sets. DTC P0785 is a type A DTC.

### Conditions for Setting the DTC

• | The system voltage is 8-16 volts.

• | The engine speed is greater than 450 RPM for 5 seconds.

• | Not in fuel cutoff.

• | All of the above conditions are met for 5 seconds and either of the following fail conditions occurs for 5 seconds:

- | The PCM commands the solenoid ON and the voltage input remains high (B+).

- | The PCM commands the solenoid OFF and the voltage input remains low (0 volts).

### Action Taken When the DTC Sets

• | The PCM illuminates the Malfunction Indicator Lamp (MIL).

• | The PCM commands a soft landing to third gear.

• | The PCM commands maximum line pressure.

• | The PCM inhibits TCC engagement.

• | The PCM inhibits fourth gear if the transmission is in hot mode.

• | The PCM freezes shift adapts from being updated.

• | DTC P0785 stores in PCM history.

### Conditions for Clearing the MIL/DTC

• | The PCM turns OFF the MIL after three consecutive trips 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 at the PCM, the transmission connector and all other circuit connecting points 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

- | Moisture intrusion

- | Corrosion

• | 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 ability of the PCM to control the solenoid.

2. This step tests for power to the 3-2 SS Valve Assembly.

3. This step tests the ability of the PCM and wiring to control the ground circuit.

4. This step tests the resistance of the Automatic Transmission Wiring Harness Assembly (A/T Wiring Harness Assembly) and the 3-2 SS Valve Assembly.

#### DTC P0785 3-2 Shift Solenoid Valve Assembly Circuit - Electrical (3.8L, VIN K)

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 |

1. Install the Scan Tool .
2. With the engine OFF, turn the ignition switch to the RUN position.

Important:: Before clearing the DTC(s), use the scan tool in order to record the Freeze Frame and Failure Records for reference. Using the Clear Info function will erase the stored Freeze Frame and Failure Records from the PCM.

3. Record the DTC Freeze Frame and Failure Records, then clear the DTC(s).

Are DTCs P0740, P0753, P0758, and P1860 also set?

--

Go to Step 3

Go to Step 4

3 |

1. Inspect the ENG CTRL fuse.
2. If the fuse is open, inspect circuit 239 (PNK), the solenoids, and the A/T Wiring Harness Assembly for a short to ground. Repair the circuit, the solenoids, and the harness if necessary.

Refer to General Electrical Diagnosis in Wiring Systems.

Did you find a short to ground condition?

--

Go to Step 16

Go to Step 5

4 | Using the transmission output control function on the scan tool, command the 3-2 SS Valve Assembly ON and OFF three times, while listening to the bottom of the transmission pan (a stethoscope may be necessary). Does the solenoid click when commanded? | -- | Go to Diagnostic Aids | Go to Step 5
5 |

1. Turn the ignition OFF.
2. Disconnect the transmission 20-way connector (additional DTCs will be set).
3. Install the J 39775 Jumper Harness on the engine side of the 20-way connector.
4. With the engine OFF, turn the ignition switch to the RUN position.
5. Connect a test lamp from J 39775 Jumper Harness cavity E to ground.

Is the test lamp ON?

--

Go to Step 7

Go to Step 6

6 | Repair the open or short to ground in ignition feed circuit 239 (PNK) to the 3-2 SS Valve Assembly. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 16 | --
7 |

1. Install a test lamp from cavity E to cavity S of the J 39775 Jumper Harness.
2. Using the transmission output control function on the scan tool, command the 3-2 SS Valve Assembly ON and OFF three times.

Is the test lamp ON when the solenoid is commanded ON, and OFF when the solenoid is commanded OFF?

--

Go to Step 9

Go to Step 8

8 |

1. Inspect circuit 687 (WHT) of the engine wiring harness for an open, short to ground or short to power condition.

Refer to General Electrical Diagnosis in Wiring Systems.

2. Repair the circuit if necessary.

Refer to Wiring Repairs in Wiring Systems.

Did you find an open, short to ground or short to power condition?

--

Go to Step 16

Go to Step 10

9 |

1. Install the J 39775 Jumper Harness on the transmission side of the 20-way connector.
2. Using the J 39200 Digital Multimeter (DMM) and J 35616-A Connector Test Adapter Kit, measure the resistance between terminal E and terminal S.

Is the resistance within the specified range?

20-32 ohms

Go to Step 12

Go to Step 11

10 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Is the replacement complete? | -- | Go to Step 16 | --
11 |

1. Disconnect the A/T Wiring Harness Assembly from the 3-2 SS Valve Assembly.
2. Measure the resistance of the 3-2 SS Valve Assembly.

Is the resistance within the specified range?

20-32 ohms

Go to Step 14

Go to Step 15

12 | Measure the resistance between terminal S and ground, and between terminal E and ground. Are both measurements greater than the specified value? | 250 K ohms | Go to Diagnostic Aids | Go to Step 13
13 |

1. Disconnect the A/T Wiring Harness Assembly from the 3-2 SS Valve Assembly.
2. Measure the resistance from the component's terminals to ground.

Are both measurements greater than the specified value?

250 K ohms

Go to Step 14

Go to Step 15

14 | Replace the A/T Wiring Harness Assembly. Refer to Torque Converter Clutch Pulse Width Modulation Solenoid, Torque Converter Clutch Solenoid, and Wiring Harness Replacement. Is the replacement complete? | -- | Go to Step 16 | --
15 | Replace the 3-2 SS Valve Assembly. Refer to Control and Shift Solenoids Replacement . Is the replacement complete? | -- | Go to Step 16 | --
16 | In order to verify your repair, perform the following procedure:

1. Select DTC.
2. Select Clear Info.
3. Drive the vehicle in D3 or D4 range and perform a 3-2 downshift. Ensure that the following conditions are met:

• | The PCM commands the 3-2 SS Valve Assembly ON and the voltage input drops to zero.

• | The PCM commands the 3-2 SS Valve Assembly OFF and the voltage input increases to B+.

• | All conditions are met for 5 seconds.

4. Select Specific DTC. Enter DTC P0785.

Has the test run and passed?

--

System OK

Go to Step 1