For 1990-2009 cars

## DTC P0753 1-2 Shift Solenoid Circuit Electrical Buick Built Before 6/17/96

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

### Circuit Description

The 1-2 Shift Solenoid Valve (1-2 SS Valve) controls the transmission fluid pressure on the 1-2 shift valve. The CLG FN/TCC fuse provides ignition voltage to the solenoid. The Output Driver Module (ODM), within the Powertrain Control Module (PCM), provides ground. The PCM monitors voltage levels at the ODM. When you command the 1-2 SS Valve ON, the PCM receives low voltage. When you command the 1-2 SS Valve OFF, the PCM receives high voltage.

DTC P0753 sets if the received voltage is outside the calibration limits. DTC P0753 is a type A DTC.

### Conditions for Setting the DTC

• | The system voltage is 10-16 volts.

• | The engine speed is greater than 500 RPM for more than 5 seconds.

• | Not in fuel shut off

• | The system voltage is 10-16 volts.

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

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

• | All conditions must be met for 5 seconds.

### Action Taken When the DTC Sets

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

• | The PCM inhibits downshifts to 2nd gear if the vehicle speed is greater than 51 km/h (32 mph).

### 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 at the transmission 7-way connector. Inspect the wiring at the 1-2 SS Valve connector. Look for the following problems:

- | 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, massage the wiring harness while watching the test equipment for a change.

• | Refer to Shift Solenoid Valve State and Gear Ratio table.

### Test Description

1. This Step isolates the fault between the engine harness and the transmission harness.

2. This Step verifies that circuit 1222 is neither open nor shorted to power.

3. This Step verifies that the 1-2 shift solenoid has neither shorted across its windings nor increased its resistance.

#### DTC P0753 1-2 Shift Solenoid Electrical (Early Buick)

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
2 |

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

Important: Before clearing the DTCs, 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.

Are DTCs P0758, P1860, and P0740 set?

--

Go to Step 3

Go to Step 6

3 | Remove the CLGFN/TCC fuse. Inspect the fuse for an open. Did you find and correct a problem? | -- | Go to Step 4 | Go to Step 5
4 | Repair short to ground in circuit 241. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | --
5 | Repair the open in circuit 241. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | --
6 |

1. Turn the ignition switch OFF.
2. Disconnect the Automatic Transmission 7-way connector.
3. Install the J 38835 Transmission Electrical Jumper on the engine harness connector.
4. Connect a test lamp from terminal E to terminal A of the jumper.

Important: Additional DTCs will set.

5. With the engine OFF, turn the ignition ON.

Is the test lamp ON?

--

Go to Step 7

Go to Step 8

7 | Inspect circuit 1222 for a short to ground. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | Go to Step 18
8 |

1. Select A/T Outputs, 1-2 Solenoid.
2. Cycle the 1-2 solenoid ON and OFF three times.

Does the test lamp cycle ON and OFF as commanded?

--

Go to Step 12

Go to Step 9

9 | Inspect circuit 1222 for an open. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | Go to Step 10
10 | Is the test lamp always OFF? | -- | Go to Step 11 | --
11 | Inspect circuit 1222 for a short to power. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | Go to Step 18
12 |

1. Turn the ignition OFF.
2. Disconnect the J 38835 Transmission Electrical Jumper from the engine harness.
3. Connect the J 38835 Transmission Electrical Jumper to the Automatic Transmission 7-way connector.
4. Connect an ohmmeter from terminal E to terminal A of the jumper.

Is the measured resistance within the specified range?

19-24ohms at 20°C (68°F)

24-31ohms at 88°C (190°F)

Go to Step 18

Go to Step 13

13 | Is the resistance greater than the specified value? | 100ohms | Go to Step 14 | Go to Step 15
14 | Inspect the RED wire circuit 839 for an open. Inspect the GRN wire circuit 1222 for an open. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | Go to Step 17
15 | Connect the ohmmeter from terminal A of the jumper to ground. Is the resistance less than the specified value? | 100ohms | Go to Step 16 | Go to Step 17
16 | Inspect the GRN wire circuit 1222 for a short to ground. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | --
17 | Replace the 1-2 Shift Solenoid. Refer to Solenoids and Wiring Harness, in On-Vehicle Service. Is the replacement complete? | -- | Go to Step 19 | --
18 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming , Section 6. Is the replacement complete? | -- | Go to Step 19 | --
19 | 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:

• | The ignition switch is ON.

• | The system voltage is 10-16 volts.

• | The engine speed is more than 500 RPM for more than 5 seconds.

• | The vehicle is not in fuel shut off.

• | Drive the vehicle through a 1-2 shift cycle.

• | The system voltage is 10-16 volts.

• | The PCM commands the solenoid ON and the voltage decreases to 0 volts.

• | The PCM commands the solenoid OFF and the voltage increases to B+.

• | All conditions must be met for 5 seconds.

4. Select Specific DTC. Enter DTC P0753.

Has the test run and passed?

--

System OK

Begin the diagnosis again. Go to Step 1

## DTC P0753 1-2 Shift Solenoid Circuit Electrical All Other Applications

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

### Circuit Description

The 1-2 Shift Solenoid Valve (1-2 SS Valve) controls the transmission fluid pressure on the 1-2 shift valve. The MISC ENG fuse provides ignition voltage to the solenoid. The Output Driver Module (ODM), within the Powertrain Control Module (PCM), provides ground. The PCM monitors voltage levels at the ODM. When you command the 1-2 SS Valve ON, the PCM receives low voltage. When you command the 1-2 SS Valve OFF, the PCM receives high voltage.

DTC P0753 sets if the received voltage is outside the calibration limits. DTC P0753 is a type A DTC.

### Conditions for Setting the DTC

• | The system voltage is 10-16 volts.

• | The engine speed is greater than 500 RPM for more than 5 seconds.

• | Not in fuel shut off

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

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

• | All conditions must be met for 5 seconds.

### Action Taken When the DTC Sets

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

• | The PCM inhibits downshifts to 2nd gear if the vehicle speed is greater than 48 km/h (30 mph).

### 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 at the transmission 7-way connector. Inspect the wiring at the 1-2 SS Valve connector. Look for the following problems:

- | 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, massage the wiring harness while watching the test equipment for a change.

### Test Description

1. This Step isolates the fault between the engine harness and the transmission harness.

2. This Step verifies that circuit 1222 is neither open nor shorted to power.

3. This Step verifies that the 1-2 shift solenoid has neither shorted across its windings nor increased its resistance.

#### DTC P0753 1-2 Shift Solenoid Electrical

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
2 |

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

Important: Before clearing the DTCs, 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.

Are DTCs P0758, P1860, and P0740 set?

--

Go to Step 3

Go to Step 6

3 | Remove the MISC ENG fuse. Inspect the fuse for an open. Did you find and correct a problem? | -- | Go to Step 4 | Go to Step 5
4 | Repair short to ground in circuit 639. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | --
5 | Repair the open in circuit 639. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | --
6 |

1. Turn the ignition switch OFF.
2. Disconnect the Automatic Transmission 7-way connector.
3. Install the J 38835 Transmission Electrical Jumper on the engine harness connector.
4. Connect a test lamp from terminal E to terminal A of the jumper.

Important: Additional DTCs will set.

5. With the engine OFF, turn the ignition ON.

Is the test lamp ON?

--

Go to Step 7

Go to Step 8

7 | Inspect circuit 1222 for a short to ground. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | Go to Step 18
8 |

1. Select A/T Outputs, 1-2 Solenoid.
2. Cycle the 1-2 solenoid ON and OFF three times.

Does the test lamp cycle ON and OFF as commanded?

--

Go to Step 12

Go to Step 9

9 | Inspect circuit 1222 for an open. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | Go to Step 10
10 | Is the test lamp always OFF? | -- | Go to Step 11 | --
11 | Inspect circuit 1222 for a short to power. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | Go to Step 18
12 |

1. Turn the ignition OFF.
2. Disconnect the J 38835 Transmission Electrical Jumper from the engine harness.
3. Connect the J 38835 Transmission Electrical Jumper to the Automatic Transmission 7-way connector.
4. Connect an ohmmeter from terminal E to terminal A of the jumper.

Is the measured resistance within the specified range?

19-24ohms at 20°C (68°F)

24-31ohms at 88°C (190°F)

Go to Step 18

Go to Step 13

13 | Is the resistance greater than the specified value? | 100ohms | Go to Step 14 | Go to Step 15
14 | Inspect the RED wire circuit 839 for an open. Inspect the GRN wire circuit 1222 for an open. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | Go to Step 17
15 | Connect the ohmmeter from terminal A of the jumper to ground. Is the resistance less than the specified value? | 100ohms | Go to Step 16 | Go to Step 17
16 | Inspect the GRN wire circuit 1222 for a short to ground. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | Go to Step 19 | --
17 | Replace the 1-2 Shift Solenoid. Refer to Solenoids and Wiring Harness, in On-Vehicle Service. Is the replacement complete? | -- | Go to Step 19 | --
18 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming , Section 6. Is the replacement complete? | -- | Go to Step 19 | --
19 | 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:

• | The ignition switch is ON.

• | The system voltage is 10-16 volts.

• | The engine speed is more than 500 RPM for more than 5 seconds.

• | The vehicle is not in fuel shut off.

• | Drive the vehicle through a 1-2 shift cycle.

• | The system voltage is 10-16 volts.

• | The PCM commands the solenoid ON and the voltage decreases to 0 volts.

• | The PCM commands the solenoid OFF and the voltage increases to B+.

• | All conditions must be met for 5 seconds.

4. Select Specific DTC. Enter DTC P0753.

Has the test run and passed?

--

System OK

Begin the diagnosis again. Go to Step 1