Circuit Description
The 2-3 shift solenoid (2-3 SS) valve controls transmission fluid pressure acting on the 1-2 and 2-3 shift valves to position the valves for the appropriate gear. The 2-3 SS valve is a normally-open exhaust valve located on the control valve body. Circuit 1039 supplies ignition voltage to the 2-3 SS valve. The output driver module (ODM), within the PCM, commands the solenoid ON or OFF by providing a ground path through circuit 1223. When the 2-3 SS valve is commanded ON, the PCM senses low voltage. When the 2-3 SS valve is commanded OFF, the PCM senses high voltage.
If the PCM detects a continuous open or short to ground in circuit 1223 or in the 2-3 SS Valve, then DTC P0758 sets. DTC P0758 is a Type A DTC.
Conditions for Setting the DTC
| • | The system voltage is 9-18 volts. |
| • | The engine speed is greater than 500 RPM for 5 seconds and 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). |
| • | Al conditions are met for 5 seconds. |
Action Taken When the DTC Sets
| • | The PCM illuminates the Malfunction Indicator Lamp (MIL). |
| • | The PCM commands 3rd gear. |
| • | The PCM commands maximum line pressure. |
| • | The PCM freezes shift adapts. |
| • | The PCM inhibits TCC. |
| • | The PCM stores DTC P0758 in PCM history. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes. |
| • | A scan tool clears the DTC from the PCM history. |
| • | The PCM clears the DTC from the PCM history if the vehicle completes 40 consecutive warm-up cycles without an 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
| • | Inspect the wiring for poor electrical connections at the PCM, the transmission 20-way connector, the 2-3 shift solenoid valve 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, massage the wiring harness while watching the test equipment for a change. |
| • | Ensure that the scan tool commanded gear has correct solenoid states and ratio. Refer to the Shift Solenoid Valve State and Gear Ratio table. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step isolates the fault between the engine harness and the transmission harness.
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This step verifies that circuit 1223 is not open or shorted to power.
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This step verifies that the 2-3 solenoid is not shorted across its windings nor increased its resistance.
-
Because of the harsh conditions inside the transmission, repairing the Automatic Transmission Wiring Harness is not acceptable. You must replace the Automatic Transmission Wiring Harness.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Were you sent here from the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls | |
2 |
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. Are DTCs P0753 or P1860 set? | -- | ||
3 |
Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | ||
4 | Repair the short to ground in circuit 1039. Replace the TRANS fuse. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
5 | Repair open in circuit 1039. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
Important: Additional DTCs will set. Is the test lamp ON? | -- | |||
7 | Inspect circuit 1223 (YEL/BLK) of the engine harness for a short to ground. Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | ||
Using the Scan Tool , cycle the 2-3 solenoid ON and OFF three times. Does the test lamp cycle ON and OFF as commanded? | -- | |||
9 | Inspect circuit 1223 (YEL/BLK) of the engine harness for an open or a short to power. Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | ||
Refer to the Connector End View . Is the measured resistance within the specified range? | 19-24 ohms at 20°C (68°F) 24-31 ohms at 88°C (190°F) | |||
11 | Is the resistance greater than the specified value? | 100 ohms | ||
12 |
Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | ||
13 | Connect a DMM from terminal B of the jumper to ground. Is the measured resistance less than the specified value? | 100 ohms | ||
14 | Inspect automatic transmission wiring harness assembly circuit 1223 (YEL) for a short to ground. Was a condition found? | -- | -- | |
15 | Replace the 2-3 Shift Solenoid. Refer to 2-3 Shift Solenoid Valve Replacement . Is the replacement complete? | -- | -- | |
16 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Is the replacement complete? | -- | -- | |
Replace the Automatic Transmission Wiring Harness Assembly. Refer to Solenoids and Wiring Harness Replacement . Is the replacement complete? | -- | -- | ||
18 | Repair circuit 1223 (YEL/BLK) of the engine harness. Is the repair complete? | -- | -- | |
19 | In order to verify your repair, perform the following procedure:
Has the test run and passed? | -- | System OK |
