The 1-2 shift solenoid (SS) valve controls the fluid flow action on the 1-2 and the 3-4 shift valves. The 1-2 SS valve is a normally-open exhaust valve that is used with the 2-3 SS valve to allow for four different shifting combinations. The 1-2 SS valve attaches to the control valve body within the transmission. The ignition voltage goes directly to the 1-2 SS valve. The powertrain control module (PCM) controls the 1-2 SS valve by providing the ground path through the 1-2 shift solenoid valve control circuit.
When the PCM detects a continuous open or short in the 1-2 SS valve circuit or the 1-2 SS valve, then DTC P0753 sets. DTC P0753 is a type C DTC. For California emissions vehicles, DTC P0753 is a type A DTC.
• | The system voltage is 8-18 volts. |
• | The engine runs more than 400 RPM for greater than 7 seconds. |
All conditions for running the DTC are met, and either of the following conditions occur for 4.3 seconds out of 5 seconds.
• | The PCM commands the solenoid on, and the voltage input remains high, B+. |
• | The PCM commands the solenoid off and the voltage input remains low. |
• | For California emission equipped vehicles, the PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met. For Federal emission equipped vehicles, the MIL is not illuminated. |
• | The PCM commands maximum line pressure. |
• | The PCM freezes shift adapts. |
• | The PCM inhibits 3-2 downshifts above 40 km/h (25 mph). |
• | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame, California only, and Failure Records, California and Federal. |
• | The PCM stores the DTC P0753 in PCM history during the second consecutive trip, California, or the first trip, Federal, in which the Conditions for Setting the DTC are met. |
• | 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. |
• | DTC P0753 defaults to an elevated line pressure condition which may result in partial TCC apply. This may produce an idle surge that could stall the engine. |
• | An open ignition feed on the Off/Run/Crank voltage circuit (CKT 1020) can cause multiple DTCs to set. |
The numbers below refer to the step numbers on the diagnostic table.
This step tests the function of the 1-2 SS valve and the internal wiring harness.
This step tests the power to the 1-2 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 wiring harness assembly and the 1-2 SS valve.
Step | Action | Value(s) | Yes | No | ||||||||||
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1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls in Engine Controls - 4.8L, 5.3L, and 6.0L | ||||||||||
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, P0758, or P1860 also set? | -- | Go to Step 3 | Go to Step 4 | ||||||||||
3 |
Refer to Wiring Repairs in Wiring Systems or to Valve Body and Pressure Switch Replacement. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 4 | ||||||||||
Using the transmission output control function on the scan tool, command the 1-2 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 in Engine Controls - 4.8L, 5.3L, and 6.0L | Go to Step 5 | |||||||||||
Does the test lamp illuminate? | -- | Go to Step 7 | Go to Step 6 | |||||||||||
6 | Repair the open or high resistance in the Off/Run/Crank voltage circuit (CKT 1020) to the 1-2 SS valve. Refer to Circuit Testing and Wiring Repairsin Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | -- | ||||||||||
Does the test lamp illuminate when you command the shift solenoid ON and turn off when you command the shift solenoid OFF? | -- | Go to Step 10 | Go to Step 8 | |||||||||||
8 | Test the 1-2 shift solenoid circuit (CKT 1222) of the 1-2 SS valve for an open or short to ground. Refer to Circuit Testing and Wiring Repairsin Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 9 | ||||||||||
9 | Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 4.8L, 5.3L, and 6.0L. Did you complete the replacement? | -- | Go to Step 17 | -- | ||||||||||
Does the resistance measure within the specified values? | 19-31 ohms | Go to Step 12 | Go to Step 11 | |||||||||||
11 |
Does the resistance measure within the specified values? | 19-31 ohms | Go to Step 15 | Go to Step 16 | ||||||||||
12 | Using the DMM, measure the resistance between terminal A and ground. Does the resistance measure greater than the specified value? | 250 K ohms | Go to Step 14 | Go to Step 13 | ||||||||||
13 |
Do both readings measure greater than the specified value? | 250 K ohms | Go to Step 15 | Go to Step 16 | ||||||||||
14 | Measure the resistance between terminal A and all other terminals, except terminal B, E, and S of the J 44152 . Refer to Automatic Transmission Inline 20-Way Connector End View. Is the resistance between terminal A and any other terminal, except terminal B, E, and S less than the specified value? | -- | Go to Step 15 | Go to Intermittent Conditions in Engine Controls - 4.8L, 5.3L, and 6.0L | ||||||||||
15 | Replace the automatic transmission wiring harness assembly. Refer to Valve Body and Pressure Switch Replacement. Did you complete the replacement? | -- | Go to Step 17 | -- | ||||||||||
16 | Replace the 1-2 SS valve. Refer to Valve Body and Pressure Switch Replacement. Did you complete the replacement? | -- | Go to Step 17 | -- | ||||||||||
17 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 18 | Go to Step 2 | ||||||||||
18 | With the scan tool, observe the stored information, capture info. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 4.8L, 5.3L, and 6.0L | System OK |