Circuit Description
The 2-3 shift solenoid valve (2-3 SS Valve) controls the fluid acting on the 2-3 shift valves. The solenoid is a normally-open exhaust valve. In combination with the 1-2 Shift Solenoid Valve (1-2 SS Valve), the 2-3 SS Valve allows four different shifting combinations. The solenoid is attached to the control valve body within the transmission. Circuit 639 supplies ignition voltage directly to the 2-3 SS Valve. The PCM controls the solenoid by providing the ground path through circuit 1223.
If the PCM detects a continuous open or short to ground in the 2-3 SS Valve circuit or in the 2-3 SS Valve, then DTC P0758 sets. DTC P0758 is a Type A DTC.
Conditions for Setting the DTC
| • | The ignition is ON. |
| • | 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). |
| • | 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 disables shift adapts. |
| • | The PCM inhibits Torque Converter Clutch. |
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 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
The numbers below refer to the step numbers on the diagnostic chart.
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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.
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Because of the harsh conditions inside the transmission, repairing the A/T Wiring Harness is not acceptable. You must replace the A/T Wiring Harness.
Step | Action | Value(s) | Yes | No | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Were you sent here from the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||||||||||
2 |
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. Are DTCs P0753 and P1860 set? | -- | ||||||||||||||
3 |
Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | ||||||||||||||
4 | Repair the short to ground in circuit 639. Refer to Troubleshooting Procedures. Did you find and correct a problem? | -- | -- | |||||||||||||
5 | Repair open in circuit 639. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | -- | |||||||||||||
Important: Additional DTCs will set. Is the test lamp ON? | -- | |||||||||||||||
7 | Inspect circuit 1223 for a short to ground. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | ||||||||||||||
Does the test lamp cycle ON and OFF as you commanded? | -- | |||||||||||||||
9 | Inspect circuit 1223 for an open. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | ||||||||||||||
10 | Is the test lamp always OFF? | -- | -- | |||||||||||||
11 | Inspect circuit 1223 for a short to power. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | ||||||||||||||
Is the measured resistance within the specified range? | 19-24ohms at 20°C (68°F) 24-31ohms at 88°C (190°F) | |||||||||||||||
13 | Is the resistance greater than the specified value? | 100ohms | ||||||||||||||
14 |
Refer to Troubleshooting Procedures, Section 8. Did you find a problem? | -- | ||||||||||||||
15 | Connect an ohmmeter from terminal B of the jumper to ground. Is the measured resistance less than the specified value? | 100ohms | ||||||||||||||
16 | Inspect Automatic Transmission (A/T) Wiring Harness circuit 1223 (YEL) for a short to ground. Did you find a problem? | -- | -- | |||||||||||||
17 | Replace the 2-3 Shift Solenoid. Refer to Solenoids and Wiring Harness, in On-Vehicle Service. Is the replacement complete? | -- | -- | |||||||||||||
18 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming , Section 6. Is the replacement complete? | -- | -- | |||||||||||||
Replace the A/T Wiring Harness. Refer to Solenoids and Wiring Harness, in On-Vehicle Service. Is the replacement complete? | -- | -- | ||||||||||||||
20 | In order to verify your repair, perform the following procedure:
Has the test run and passed? | -- | System OK |
