Circuit Description
The 2-3 shift solenoid (SS) valve controls fluid 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 through the 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 8.0-18.0 volts. |
| • | The engine is running more than 300 RPM 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 (Calif. only) and Failure Records (Calif. 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
| • | Refer to Shift Solenoid Valve State and Gear Ratio. |
| • | DTC P0758 defaults to an elevated line pressure condition which may result in TCC partial apply. This may induce idle surge and engine stall. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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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 A Diagnostic System Check - Engine Controls | |||||||||||
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? | -- | ||||||||||||
3 |
Refer to Wiring Repairs in Wiring Systems or to Wiring Harness Replacement. Did you find and correct the condition? | -- | ||||||||||||
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 | ||||||||||||
Does the test lamp illuminate? | -- | |||||||||||||
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? | -- | -- | |||||||||||
Does the test lamp illuminate when you command the shift solenoid ON and turn off when you command the shift solenoid OFF? | -- | |||||||||||||
8 | 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? | -- | ||||||||||||
9 | Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls. Did you complete the replacement? | -- | -- | |||||||||||
Does the resistance measure within the specified values? | 19-31 ohms | |||||||||||||
11 |
Does the resistance measure within the specified values? | 19-31 ohms | ||||||||||||
12 | Measure the resistance between terminal B and a good ground. Use the J 39200 DMM. Does the resistance measure greater than the specified value? | 250 K ohms | ||||||||||||
13 |
Do both readings measure greater than the specified value? | 250 K ohms | ||||||||||||
14 | Measure the resistance between terminal B and all other terminals, except terminals 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 terminals A, E, and S less than the specified value? | -- | Go to Intermittent Conditions | |||||||||||
15 | Replace the automatic transmission wiring harness assembly. Refer to Wiring Harness Replacement. Did you complete the replacement? | -- | -- | |||||||||||
16 | Replace the 2-3 SS valve. Refer to Control Valve Body Replacement. Did you complete the replacement? | -- | -- | |||||||||||
17 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK |
