DTC P0758 2-3 (B) Shift Solenoid Electrical. Cadillac Concours 1996

For 1990-2009 cars

Table 1: | Shift Solenoid Valve Status
Table 2: | DTC P0758 2-3 Shift Solenoid Valve Electrical

Automatic Transmission Components
Brake Switch, Solenoids, and VSS
Handling ESD Sensitive Parts Notice
OBD II Symbol Description Notice

### Circuit Description

The 2-3 shift solenoid valve controls the transmission fluid to the 2-3 shift valve. Ignition voltage is provided to the solenoid. The PCM Output Driver Module (ODM) provides the ground. When the 2-3 shift solenoid valve is commanded ON, the PCM senses 0 volts. When the 2-3 shift solenoid valve is commanded OFF, the PCM senses ignition voltage.

When the PCM detects voltage limits that do not meet the calibration, then DTC P0758 sets. DTC P0758 is a Type A DTC.

### Conditions for Setting the DTC

• | No ODM DTC P1650 set.

• | The engine has been running for more than 5 seconds.

• | The PCM detects an open, a short to ground, or a short to power on the 2-3 shift solenoid valve circuits within 5 seconds.

### Action Taken When the DTC Sets

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

• | SERVICE ENGINE SOON, SERVICE TRANSMISSION displays on the Driver Information Center (DIC).

• | The PCM commands 2nd gear.

• | The PCM commands default line pressure.

• | The PCM disables steady state adapts.

• | The PCM disables garage shift adapts.

• | The PCM inhibits Torque Converter Clutch.

• | The PCM inhibits torque management.

### 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 for poor electrical connections at the transmission 20-way connector. Inspect the wiring for poor electrical connections at the 2-3 Shift Solenoid Valve Connector. Look for the following conditions:

- | A bent terminal

- | A backed out terminal

- | A damaged terminal

- | Poor terminal tension

- | A chafed wire

• | When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.

#### Shift Solenoid Valve Status

Gear Range | 1-2 Shift Solenoid | 2-3 Shift Solenoid
--- | --- | ---
Park, Reverse, Neutral | ON | OFF
First | ON | OFF
Second | OFF | OFF
Third | OFF | ON
Fourth | ON | ON

### Test Description

The numbers below refer to the step numbers on the diagnostic chart.

1. This Step verifies that you have performed the Powertrain On-Board Diagnostic System Check.

2. This Step inspects the ECS fuse for an open.

3. This Step verifies that the open fuse was caused by a short to ground in circuit 839.

4. This Step verifies that the fuse was not open and that circuit 839 must be inspected for an open.

5. This Step verifies that the 2-3 Shift Solenoid Valve is operating and that an intermittent condition may have set the DTC.

6. This Step isolates the Automatic Transmission Wiring Harness so that you can diagnose the Engine Wiring Harness. Use the J 35616-A Test Connector Adapter Kit in order to avoid damaging the terminals.

7. This Step verifies that the test lamp is ON and that circuit 1223 of the Engine Wiring Harness has been inspected for a short to ground.

8. This Step isolates circuit 1223 of the Engine Wiring Harness for an open or a short to power.

9. This Step verifies that the test lamp is OFF and that circuit 1223 of the Engine Wiring Harness has been inspected for an open.

10. This Step isolates circuit 1223 for a short to power.

11. This Step verifies that the test lamp is OFF and that no open is found in circuit 1223. The Engine Wiring Harness is inspected for a short to power.

12. This Step isolates the Engine Wiring Harness so that you can diagnose the Automatic Transmission Wiring Harness. Use the J 35616-A Test Connector Adapter Kit in order to avoid damaging the terminals.

13. This Step measures a resistance value above the high parameter.

14. This Step inspects circuit 741 and circuit 1223 of the A/T Wiring Harness for an open. If you find an open in the transmission harness, you must replace the harness.

15. This Step measures for a short to ground in circuit 1223.

16. This Step verifies that the resistance is less than 100 ohms, and that circuit 1223 has been inspected for a short to ground. If you find a short to ground in the transmission harness, you must replace the harness.

17. This Step replaces the 2-3 Shift Solenoid Valve after you have examined all the circuits.

18. This Step replaces the PCM after you have examined all the circuits and components.

#### DTC P0758 2-3 Shift Solenoid Valve Electrical

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to A Powertrain On Board Diagnostic (OBD) System Check

2

1. Install the scan tool (tech 1) .
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. The Clear Info function will erase the data.

3. Record the DTC Freeze Frame and Failure Records.

Are DTCs P0753 or P1860 set?

--

Go to Step 3

Go to Step 6

3

1. Remove the ECS fuse.
2. Inspect the fuse for an open.

Refer to Electrical Diagnosis, Section 8.

Did you find and correct the condition?

--

Go to Step 4

Go to Step 5

4 | Repair the short to ground in circuit 839. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | Go to Step 20 | --
5 | Repair the open in circuit 839. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | Go to Step 20 | --

6

1. Enter A/T Outputs, 2-3 Sol.
2. Cycle the 2-3 Shift Solenoid ON and OFF three times.

Listen at the transmission side cover. Does the 2-3 Shift Solenoid Valve click when commanded ON?

--

Go to Diagnostic Aids

Go to Step 7

7

1. Turn the ignition OFF.
2. Disconnect the transmission 20-way connector.
3. Connect a test lamp from terminal E to terminal B.
4. With the engine OFF, turn the ignition switch to the RUN position.

Is the test lamp ON?

--

Go to Step 8

Go to Step 9

8 | Inspect circuit 1223 of the Engine Wiring Harness for a short to ground. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 19
9 | Cycle the 2-3 Shift Solenoid ON and OFF three times. Does the test lamp cycle ON and OFF as commanded? | -- | Go to Step 13 | Go to Step 10
10 | Inspect circuit 1223 of the Engine Wiring Harness for an open. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 19
11 | Is the test lamp always OFF? | -- | Go to Step 12 | --
12 | Inspect and repair circuit 1223 of the Engine Wiring Harness for a short to power. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 19

13

1. Turn the ignition OFF.
2. Connect Jumper Harness J 39775 to the Automatic Transmission Wiring Harness 20-way connector.
3. Connect an ohmmeter from terminal E to terminal B.

Does the ohmmeter display a resistance within the specified range?

20-40ohms

Go to Step 19

Go to Step 14

14 | Is the resistance greater than the specified value? | 50ohms | Go to Step 15 | Go to Step 16
15 | Inspect and repair circuit 741 and circuit 1223 of the Automatic Transmission Wiring Harness for an open. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | Go to Step 20 | --
16 | Connect the Ohmmeter from terminal B to ground. Is the resistance less than the specified value? | 100ohms | Go to Step 17 | --
17 | Inspect and repair circuit 1223 of the Automatic Transmission Wiring Harness for a short to ground. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 18
18 | Replace the 2-3 Shift Solenoid Valve. Refer to 2-3 Shift Solenoid Valve Replacement in On-Vehicle Service. Is the replacement complete? | -- | Go to Step 20 | --
19 | Replace the PCM. Refer to PCM Replacement/Programming Section 6. Is the replacement complete? | -- | Go to Step 20 | --

20

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:

3.1. | Start the engine.

3.2. | Allow the engine to run for 30 seconds.

4. Select Specific DTC. Enter DTC P0758.

Has the test run and passed?

--

System OK

Begin the diagnosis again. Go to Step 1