| Table 1: | Shift Solenoid Valid Combination Table |
DTC Description
This diagnostic procedure covers the following DTCs:
| • | DTC P0751--1-2 Shift Solenoid A Performance or Stuck OFF. |
| • | DTC P0752--1-2 Shift Solenoid A Performance or Stuck ON. |
| • | DTC P0753--1-2 Shift Solenoid A Electrical. |
Circuit Description
The 1-2 shift solenoid A controls the fluid flow acting on the 1-2 and 3-4 shift valves. The 1-2 shift solenoid A is a normally open-exhaust valve that is used with the 2-3 shift solenoid B valve, to allow four different shifting combinations. The solenoid attaches to the control valve body within the transmission. The 1-2 shift solenoid a receives ignition voltage through circuit 339. The powertrain control module (PCM) controls the solenoid by providing the ground path on circuit 1222.
When the PCM detects a shift pattern other than what it expects, or a fault in the electrical circuit, a 1-2 shift solenoid A DTC sets.
Conditions for Running DTCs
P0751
| • | No TPS, VSS, TCC solenoid, other 1-2 shift solenoid, or TFP manual valve position switch DTCs are set. |
| • | The engine speed is greater than 450 RPM for 5 seconds. |
| • | The engine is not in fuel cut-off. |
| • | The gear range is D4. |
| • | The TP angle is greater than 10 percent. |
| • | The transmission fluid temperature is between 20-130°C. |
| • | The system voltage is between 10.0-18.0 volts. |
| • | The engine torque is between 68-542 N·m. |
| • | The transmission output speed is 150 RPM or greater. |
P0752
| • | No TPS, VSS, TCC solenoid, other 1-2 shift solenoid, 2-3 shift solenoid, or TFP manual valve position switch DTCs are set. |
| • | The engine speed is greater than 450 RPM for 5 seconds. |
| • | The engine is not in fuel cut-off. |
| • | The gear range is D4. |
| • | The TP angle is greater than 10 percent. |
| • | The transmission fluid temperature is 20-130°C. |
| • | The system voltage is 10.0-18.0 volts. |
| • | The transmission output speed is 150 RPM or greater. |
P0753
| • | The system voltage is between 8.0-18 volts. |
| • | The engine speed is greater than 300 RPM for 5 seconds. |
| • | The engine is not in fuel cut-off. |
Conditions for Setting DTCs
P0751
DTC P0751 sets if both of the following conditions occur twice:
Condition 1
| • | The PCM commands first gear for 2 seconds. |
| • | The estimated gear ratio is 1.2-1.8. |
| • | Speed ratio is greater than 0.35. Speed ratio is engine speed divided by transmission output speed. |
| • | All conditions are met for 0.5 second. |
Condition 2
| • | The PCM commands fourth gear for 1 second. |
| • | The estimated gear ratio is 0.95-1.15. |
| • | Speed ratio is greater than 0.85. Speed ratio is engine speed divided by transmission output speed. |
| • | All conditions are met for 6 seconds. |
P0752
DTC P0752 sets if both of the following conditions occur twice:
Condition 1
| • | The PCM commands second gear for 1 second. |
| • | The engine torque is 33-610 N·m. |
| • | The estimated gear ratio is 3.0-3.3. |
| • | Speed ratio is greater than 0.5. Speed ratio is engine speed divided by transmission output speed. |
| • | All conditions are met for 2 seconds. |
Condition 2
| • | The PCM commands third gear for 1 second. |
| • | The engine torque is 68-542 N·m. |
| • | The estimated gear ratio is 0.65-0.9. |
| • | Speed ratio is greater than 0.5. Speed ratio is engine speed divide by transmission output speed. |
| • | All conditions are met for 3 seconds. |
P0753
| • | The PCM commands the solenoid ON and the voltage input remains high (12 volts). |
| OR |
| • | The PCM commands the solenoid OFF and the voltage input remains low (0 volts). |
Conditions for Clearing the DTC
The 1-2 shift solenoid A DTCs are Type B DTCs. Refer to Diagnostic Starting Point - Automatic Transmission for Action Taken when Type B DTCs set and Conditions for Clearing Type B DTCs.
Additional Information
| • | Verify that the transmission shift pattern complies with the shift pattern charts. Refer to Functional Test. Other internal transmission failures may cause more than one shift to occur. |
| • | Refer to Transmission General Information for details of the 1-2 shift solenoid A operation. |
| • | For an intermittent fault condition, refer to Intermittent Conditions. |
| • | Since a fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic procedure for shorted terminals or poor wiring connection before replacing any component. Refer to Testing for Intermittent Conditions and Poor Connections for information on electrical fault diagnosis. |
Gear | 1-2 Shift Solenoid A | 2-3 Shift Solenoid B | Gear Ratio |
|---|---|---|---|
1 | ON | ON | 3.059:1 |
2 | OFF | ON | 1.625:1 |
3 | OFF | OFF | 1.000:1 |
4 | ON | OFF | 0.696:1 |
Test Description
The following numbers refer to the step numbers in the diagnostic chart.
5 A mechanical fault causes DTC P0752 or P0753 to set.
10 This diagnostic table only tests the 1-2 shift solenoid A circuits outside the transmission. Check for damaged wiring or poor connections inside the transmission assembly before replacing the 1-2 shift solenoid A. Measure the resistance of the 1-2 shift solenoid A. Refer to Transmission General Specifications.
Step | Action | Yes | No | ||||
|---|---|---|---|---|---|---|---|
1 | Was the main Diagnostic Table performed? | Go to Step 2 | |||||
2 |
Does DTC P0751, P0752, or P0753 fail this ignition cycle? | Go to Step 3 | Refer to Diagnostic Aids for the 1-2 Shift Solenoid A DTCs | ||||
3 | Is DTC P0751 and/or P0752. but not P0753, set? | Go to Step 6 | Go to Step 4 | ||||
4 | Is DTC P0753 set? | Go to Step 6 | -- | ||||
5 | Inspect the shift solenoid/hydraulic circuit for the following conditions :
Refer to Functional Test. Was any fault found and rectified? | Go to Step 12 | Refer to Diagnostic Aids for the 1-2 Shift Solenoid A DTCs | ||||
6 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 9 | ||||
7 |
Does the test lamp illuminate ON and OFF when the 1-2 shift solenoid A is commanded ON and OFF? | Go to Step 10 | Go to Step 8 | ||||
8 | Test the 1-2 shift solenoid A control circuit for an open circuit, shot to ground, high resistance, or short to voltage fault condition. Refer to Testing for Intermittent Conditions and Poor Connections for information on electrical fault diagnosis. Was any fault found and rectified? | Go to Step 12 | Go to Step 11 | ||||
9 | Repair the open circuit, short to ground, high resistance, or short to voltage fault condition in the 1-2 shift solenoid A ignition voltage circuit. Refer to Testing for Intermittent Conditions and Poor Connections for information on electrical wiring repair procedures. Was the repair completed? | Go to Step 12 | -- | ||||
10 |
Important: Check for damaged wiring (short to ground, short to voltage, high resistance or open circuit) or poor connections inside the transmission assembly before replacing the 1-2 shift solenoid A. Replace the 1-2 shift solenoid A. Refer to 1-2 Shift Solenoid Valve Replacement. Was the repair completed? | Go to Step 12 | -- | ||||
11 | Replace the PCM. Refer to Powertrain Control Module Replacement. Was the repair completed? | Go to Step 12 | -- | ||||
12 |
Do any 1-2 shift solenoid A DTCs fail this ignition cycle? | Go to Step 2 | Go to Step 13 | ||||
13 | Using Tech 2, select the DTC display function. Are there any DTCs displayed? | Go to the appropriate DTC Table | System OK | ||||
When all diagnosis and repairs are completed, check the powertrain management system for correct operation. | |||||||
