The 1-2 Shift Solenoid Valve (1-2 SS Valve) controls the fluid flow acting on the 1-2 and 3-4 shift valve. The solenoid is a normally-open exhaust valve. The combination of the 2-3 Shift Solenoid Valve and the 1-2 SS Valve allows four different shifting combinations. The solenoid attaches to the control valve body within the transmission. Circuit 439 supplies ignition voltage directly to the 1-2 SS Valve. The PCM controls the solenoid by providing a ground path through circuit 1222.
If the PCM detects a continuous open or a short to ground in the 1-2 SS Valve circuit or the 1-2 SS Valve, then DTC P0753 sets. DTC P0753 is a type A DTC.
| • | The engine speed is greater than 400 RPM for 5 seconds and not in fuel cut off. | 
| • | The system voltage is 10-16 volts. | 
| • | The PCM commands the solenoid ON and the voltage remains high (Battery Voltage). | 
| • | The PCM commands the solenoid OFF and the voltage remains low (0 volts). | 
| • | All conditions met for 5 seconds | 
| • | The PCM commands D2 line pressure. | 
| • | The PCM freezes shift adapts from being updated. | 
| • | The PCM inhibits downshifts to 2nd when the speed is greater than 30 mph. | 
| • | The PCM illuminates the Malfunction Indicator Lamp (MIL). | 
| • | 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. | 
| • | Inspect the wiring for any poor electrical connections at the PCM. Inspect the wiring at the TCC brake switch. 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 an open, massage the wiring harness while watching the test equipment for changes. | 
| • | An open feed circuit can set multiple DTCs. | 
| • | Refer to Shift Solenoid Valve State and Gear Ratio . | 
The numbers below refer to the step numbers on the diagnostic table.
This step verifies that the 1-2 SS Valve and the Automatic Transmission Wiring Harness Assembly are functioning normally.
This step verifies that the ignition supplies power to the 1-2 SS Valve through the PCM IGN fuse.
This step verifies that the valve's resistance is within specifications.
Step  | Action  | Value(s)  | Yes  | No  | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1  | Was the Powertrain On-Board Diagnostic (OBD) System Check performed?  | --  | Go to Powertrain On Board Diagnostic (OBD) System Check , Section 6.  | |||||||||||||
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.  | --  | ||||||||||||||
3  | 
 
 
 
 
 Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem?  | --  | --  | |||||||||||||
Using the scan tool, command the 1-2 SS Valve ON and OFF three times while listening to the bottom of the transmission pan (a stethoscope may be necessary). Did the solenoid click when commanded?  | --  | |||||||||||||||
5  | 
 
 
 
 
 
 
 Did you find and correct a problem?  | --  | Go to Diagnostic Aids  | |||||||||||||
 Did the test lamp Illuminate?  | --  | |||||||||||||||
7  | 
 Important: Ground pin R of the J 39775 Jumper Harness. Does the test lamp illuminate when you command the solenoid valve ON, and turn OFF when you command the solenoid valve OFF?  | --  | ||||||||||||||
8  | Repair the open in the ignition feed circuit 439 (PNK) to the 1-2 SS Valve. Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem?  | --  | --  | |||||||||||||
9  | Monitor the test lamp. Was the test lamp OFF continuously?  | --  | ||||||||||||||
10  | 
 Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem?  | --  | ||||||||||||||
11  | Was the test lamp illuminated continuously?  | --  | --  | |||||||||||||
12  | 
 Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem?  | --  | ||||||||||||||
13  | 
 
 
 
 Did you find and correct a problem?  | --  | ||||||||||||||
14  | 
 Are both readings greater than the specified value?  | 250kohms  | ||||||||||||||
15  | 
 Is the resistance within the specified range?  | 19-31ohms  | Go to Diagnostic Aids  | |||||||||||||
 Is the resistance within the specified range?  | 19-31ohms  | |||||||||||||||
17  | 
 Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem?  | --  | --  | |||||||||||||
18  | 
 Are both readings greater than the specified value?  | 250kohms  | ||||||||||||||
19  | 
 Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem?  | --  | --  | |||||||||||||
20  | Replace the 1-2 SS Valve. Refer to Control Valve Body and Pressure Switch, in On-Vehicle Service. Is the replacement complete?  | --  | --  | |||||||||||||
21  | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming , Section 6. Is the replacement complete?  | --  | --  | |||||||||||||
22  | 
 
 
 
 Has the test run and passed?  | --  | System OK  | 
The 1-2 Shift Solenoid Valve (1-2 SS Valve) controls the fluid flow acting on the 1-2 and 3-4 shift valve. The solenoid is a normally-open exhaust valve. The combination of the 2-3 Shift Solenoid Valve and the 1-2 SS Valve allows four different shifting combinations. The solenoid attaches to the control valve body within the transmission. Circuit 439 supplies ignition voltage directly to the 1-2 SS Valve. The PCM controls the solenoid by providing a ground path through circuit 1222.
If the PCM detects a continuous open or a short to ground in the 1-2 SS Valve circuit or the 1-2 SS Valve, then DTC P0753 sets. DTC P0753 is a type A DTC.
| • | The ignition is ON. | 
| • | The system voltage is 10-17 volts. | 
| • | The PCM commands the solenoid ON and the voltage remains high (Battery Positive Voltage). | 
| • | The PCM commands the solenoid OFF and the voltage remains low (0 volts). | 
| • | All conditions met for 5 seconds | 
| • | The PCM commands maximum line pressure. | 
| • | The PCM freezes shift adapts from being updated. | 
| • | The PCM illuminates the Malfunction Indicator Lamp (MIL). | 
| • | 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. | 
| • | Inspect the wiring for any poor electrical connections at the PCM. Inspect the wiring at the TCC brake switch. 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 an open, massage the wiring harness while watching the test equipment for a change. | 
| • | An open feed circuit can set multiple DTCs. | 
| • | Refer to Shift Solenoid Valve State and Gear Ratio . | 
The numbers below refer to the step numbers on the diagnostic table.
This step verifies that the 1-2 SS Valve and the Automatic Transmission Wiring Harness Assembly are functioning normally.
This step verifies that the ignition supplies power to the 1-2 SS Valve through the PCM IGN fuse.
This step verifies that the valve's resistance is within specifications.
Step  | Action  | Value(s)  | Yes  | No  | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1  | Was the Powertrain On-Board Diagnostic (OBD) System Check performed?  | --  | Go to Powertrain On Board Diagnostic (OBD) System Check , Section 6.  | |||||||||||||
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.  | --  | ||||||||||||||
3  | 
 
 
 
 
 Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem?  | --  | --  | |||||||||||||
Using the scan tool, command the 1-2 SS Valve ON and OFF three times while listening to the bottom of the transmission pan (a stethoscope may be necessary). Did the solenoid click when commanded?  | --  | |||||||||||||||
5  | 
 
 
 
 
 
 
 Did you find and correct a problem?  | --  | Go to Diagnostic Aids  | |||||||||||||
 Did the test lamp Illuminate?  | --  | |||||||||||||||
7  | 
 Does the test lamp illuminate when you command the solenoid valve ON, and turn OFF when you command the solenoid valve OFF?  | --  | ||||||||||||||
8  | Repair the open or short to ground in the ignition feed circuit 439 (PNK) to the 1-2 SS Valve. Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem?  | --  | --  | |||||||||||||
9  | Monitor the test lamp. Was the test lamp OFF continuously?  | --  | ||||||||||||||
10  | 
 
 
 
 Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem?  | --  | ||||||||||||||
11  | Was the test lamp illuminated continuously?  | --  | --  | |||||||||||||
12  | 
 Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem?  | --  | ||||||||||||||
13  | 
 
 
 
 Did you find and correct a problem?  | --  | ||||||||||||||
14  | 
 Are both readings greater than the specified value?  | 250kohms  | ||||||||||||||
15  | 
 Is the resistance within the specified range?  | 19-31ohms  | Go to Diagnostic Aids  | |||||||||||||
 Is the resistance within the specified range?  | 19-31ohms  | |||||||||||||||
17  | 
 Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem?  | --  | --  | |||||||||||||
18  | 
 Are both readings greater than the specified value?  | 250kohms  | ||||||||||||||
19  | 
 Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem?  | --  | --  | |||||||||||||
20  | Replace the 1-2 SS Valve. Refer to Control Valve Body and Pressure Switch, in On-Vehicle Service. Is the replacement complete?  | --  | --  | |||||||||||||
21  | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming , Section 6. Is the replacement complete?  | --  | --  | |||||||||||||
22  | 
 
 
 
 Has the test run and passed?  | --  | System OK  |