DTC P0758 Gas
Circuit Description
The 2-3 shift solenoid (SS) valve controls fluid of the 2-3 shift valve. The 2-3 SS valve is a normally-open exhaust valve used with the 1-2 SS valve in order to allow four different shifting combinations. The 2-3 SS valve attaches to the control valve body within the transmission. The ignition voltage goes directly to the 2-3 SS valve. The powertrain control module (PCM) controls the 2-3 SS valve by providing a ground path through the 2-3 shift solenoid valve control circuit.
If the PCM detects a continuous open or short in the 2-3 SS valve circuit or the 2-3 SS valve, then DTC P0758 sets. DTC P0758 is a type C DTC. For California emissions vehicles, DTC P0758 is a type A DTC.
Conditions for Running the DTC
| • | The system voltage is 8-18 volts. |
| • | The engine is running for more than 7 seconds. |
Conditions for Setting the DTC
The above conditions are met and either of the following conditions occur for 4.3 out of 5 seconds.
| • | The PCM commands the 2-3 SS valve ON, and the voltage input remains high, B+. |
| • | The PCM commands the 2-3 SS valve OFF, and the voltage input remains low, 0 volts. |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) for California emission vehicles. |
| • | The PCM commands a soft landing to second gear. |
| • | The PCM commands maximum line pressure. |
| • | The PCM freezes shift adapts form being updated. |
| • | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame, California only, and Failure Records, California and Federal. |
| • | The PCM stores DTC P0758 in PCM history. |
Conditions for Clearing the MIL/DTC
| • | For California emissions, the PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes. |
| • | A scan tool can clear the MIL/DTC. |
| • | For California emissions, the PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring. |
| • | For Federal emissions, the PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring. |
| • | The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long enough in order to power down the PCM. |
Diagnostic Aids
DTC P0758 defaults to an elevated line pressure condition which may result in partial TCC apply. This may produce an idle surge that could stall the engine.
Refer to Shift Solenoid Valve State and Gear Ratio .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the function of the 2-3 SS valve and the internal wiring harness.
-
This step tests the power to the 2-3 SS valve from the ignition through the fuse.
-
This step tests the ability of the PCM and the wiring to control the ground circuit.
-
This step measures the resistance of the automatic transmission (AT) wiring harness assembly and the 2-3 SS valve.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls in Engine Controls - 8.1L | ||||||
2 |
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the PCM. Were DTCs P0753, or P1860 also set? | -- | Go to Step 3 | Go to Step 4 | ||||||
3 |
Refer to Wiring Repairs in Wiring Systems or Valve Body and Pressure Switch Replacement . Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 4 | ||||||
Using the scan tool output control function, command the 2-3 SS valve ON and OFF three times while listening to the bottom of the transmission pan. Use a stethoscope if needed. Does the solenoid click when commanded? | -- | Go to Intermittent Conditions in Engine Controls - 8.1L | Go to Step 5 | |||||||
Does the test lamp illuminate? | -- | Go to Step 7 | Go to Step 6 | |||||||
6 | Repair the open or high resistance in the Off/Run/Crank voltage circuit (CKT 1020) of the 2-3 SS valve. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 19 | -- | ||||||
Does the test lamp illuminate when you command the shift solenoid ON and go out when you command the shift solenoid OFF? | -- | Go to Step 10 | Go to Step 8 | |||||||
8 | Is the test lamp always ON? | -- | Go to Step 10 | Go to Step 9 | ||||||
9 | Test the control circuit (CKT 1223) of the 2-3 SS valve for an open or short to power between the PCM connector C2 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 11 | ||||||
10 | Test the 2-3 shift solenoid valve control circuit (CKT 1223) of the 2-3 SS valve for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 11 | ||||||
11 | Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 8.1L. Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||
Does the resistance measure within the specified values? | 19-31 ohms | Go to Step 14 | Go to Step 13 | |||||||
13 |
Does the resistance measure within the specified values? | 19-31 ohms | Go to Step 17 | Go to Step 18 | ||||||
14 | Using the DMM, measure the resistance between terminal B and a good ground. Does the resistance measure greater than the specified value? | 250 K ohms | Go to Step 16 | Go to Step 15 | ||||||
15 |
Do both readings measure greater than the specified value? | 250 K ohms | Go to Step 17 | Go to Step 18 | ||||||
16 | Measure the resistance between terminal B and all other terminals, except terminal A, E, and S of the J 44152 . Refer to Automatic Transmission Inline Harness Connector End View . Is the resistance between terminal B and any other terminal, except terminal A, E, and S less than the specified value? | 250 K ohms | Go to Step 17 | Go to Intermittent Conditions in Engine Controls - 8.1L | ||||||
17 | Replace the automatic transmission wiring harness assembly. Refer to Valve Body and Pressure Switch Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||
18 | Replace the 2-3 SS valve. Refer to Valve Body and Pressure Switch Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||
19 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK | Go to Step 1 |
DTC P0758 Diesel
Circuit Description
The 2-3 shift solenoid (SS) valve controls the fluid flow acting on the 2-3 shift valve. The 2-3 SS valve is a normally-open exhaust valve used with the 1-2 SS valve in order to allow four different shifting combinations. The 2-3 SS valve attaches to the control valve body within the transmission. The ignition voltage goes directly to the 2-3 SS valve. The powertrain control module (PCM) controls the 2-3 SS valve by providing a ground path.
If the PCM detects a continuous open or short to ground in the 2-3 SS valve circuit or the 2-3 SS valve, then DTC P0758 sets. DTC P0758 is a type A DTC.
Conditions for Running the DTC
| • | The engine is running for greater than 7 seconds. |
| • | The system voltage is 8-18 volts. |
Conditions for Setting the DTC
The PCM detects either of the following fail conditions for 4.3 out of 5 seconds.
| • | The PCM commands the solenoid ON and voltage input remains high, B+. |
| • | The PCM commands the solenoid OFF and voltage input remains low, 0 volts. |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL). |
| • | The PCM commands an immediate landing to second gear. |
| • | The PCM commands maximum line pressure. |
| • | The PCM freezes shift adapts. |
| • | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records. |
| • | The PCM stores DTC P0758 in PCM history. |
Conditions for Clearing the MIL/DTC
| • | For Federal and California emissions, the PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes. |
| • | A scan tool can clear the MIL/DTC. |
| • | For Federal and California emissions, the PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring. |
| • | For vehicles equal to or greater than 15,000 lbs GVW, the PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring. |
| • | The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long enough in order to power down the PCM. |
Diagnostic Aids
| • | DTC P0758 defaults to an elevated line pressure condition which may result in partial TCC apply. This may produce an idle surge that could stall the engine. |
| • | An open ignition feed circuit can cause multiple DTCs to set. |
| • | Refer to Shift Solenoid Valve State and Gear Ratio table. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the function of the 2-3 SS valve and the automatic transmission wiring harness assembly.
-
This step tests the power circuit to the 2-3 SS valve.
-
This step tests for the resistance of the 2-3 SS valve.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls in Engine Controls - 6.5L | ||||||
2 |
Important: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data. Is DTC P0753 or DTC P1860 set? | -- | Go to Step 3 | Go to Step 4 | ||||||
3 | Inspect the transmission fuse for an open. Is the fuse open? | -- | Go to Step 12 | Go to Step 5 | ||||||
Use the scan tool in order to command the 2-3 SS valve 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 Intermittent Conditions in Engine Controls - 6.5L | Go to Step 5 | |||||||
Refer to Automatic Transmission Inline Harness Connector End View . Does the test lamp illuminate? | -- | Go to Step 6 | Go to Step 15 | |||||||
6 |
Refer to Automatic Transmission Inline Harness Connector End View . Does the test lamp turn ON and OFF with each command? | -- | Go to Step 8 | Go to Step 7 | ||||||
7 | Is the test lamp always ON? | -- | Go to Step 16 | Go to Step 17 | ||||||
8 |
Refer to Automatic Transmission Inline Harness Connector End View . Does the resistance measure within the specified range? | 19-31 ohms | Go to Step 9 | Go to Step 10 | ||||||
9 | Measure the resistance from terminal B to ground and terminal E to ground. Do both readings measure greater than the specified value? | 250 K ohms | Go to Diagnostic Aids | Go to Step 11 | ||||||
Does the resistance measure within the specified range? | 19-31 ohms | Go to Step 18 | Go to Step 19 | |||||||
11 |
Do both readings measure greater than the specified value? | 250 K ohms | Go to Step 18 | Go to Step 19 | ||||||
12 |
Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics in Wiring Systems for complete circuit distribution. Test the voltage circuit (CKT 1020) of the 2-3 SS valve for a short to ground between the IP fuse block and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 21 | Go to Step 13 | ||||||
13 |
Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics in Wiring Systems for complete circuit distribution. Test the voltage circuit (CKT 839) of the 2-3 SS valve for a short to ground between the AT inline 20-way connector and the 2-3 SS valve. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find a short to ground condition? | -- | Go to Step 18 | Go to Step 14 | ||||||
14 |
Did you complete the replacement? | -- | Go to Step 21 | -- | ||||||
15 |
Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics in Wiring Systems for complete circuit distribution. Test the voltage circuit (CKT 1020) of the 2-3 SS valve for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 21 | -- | ||||||
16 | Test the 2-3 shift solenoid valve control circuit (CKT 1223) of the 2-3 SS valve for a short to ground between the PCM connector C3-C6 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 21 | Go to Step 20 | ||||||
17 | Test the 2-3 shift solenoid valve control circuit (CKT 1223) of the 2-3 SS valve for an open or short to power between the PCM connector C3-C6 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 21 | Go to Step 20 | ||||||
18 | Replace the AT wiring harness assembly. Refer to Valve Body and Pressure Switch Replacement . Did you complete the replacement? | -- | Go to Step 21 | -- | ||||||
19 | Replace the 2-3 SS valve. Refer to Valve Body and Pressure Switch Replacement . Did you complete the replacement? | -- | Go to Step 21 | -- | ||||||
20 | Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 6.5L. Did you complete the replacement? | -- | Go to Step 21 | -- | ||||||
21 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK | Go to Step 1 |
