Circuit Description
The 1-2/3-4 shift solenoid valve is a normally closed shift
solenoid that controls the positioning of the 1-2/3-4 shift valve.
When the solenoid is closed, D32/1-2 fluid is blocked from acting on
the solenoid end of the 1-2/3-4 shift valve. When the solenoid
opens, D32/1-2 fluid pressure flows through the solenoid, and the valve
moves against spring force.
When the TCM detects a 2-2/3-3 shift pattern, then DTC P0752
will set. DTC P0752 is a type B DTC.
Conditions for Running the DTC
• | The Transmission is in drive range (D). |
• | No Trans Range Switch DTC P0705. |
• | No Output Speed Sensor DTC P0722. |
• | No 1-2/3-4 Shift Solenoid Valve DTC P0753. |
• | No 2-3 Shift Solenoid Valve DTC P0758. |
• | No TCM Internal - Watchdog Operation DTC P1600. |
• | No TCM System Reset DTC P1625. |
• | No TCC Enable Solenoid Circuit - Electrical DTC P0743. |
• | No Throttle Position Signal DTC P1890. |
All the above conditions must be present, plus one of the following
conditions:
Condition 1:
• | The commanded gear is 1st for greater than 1.5 seconds. |
• | The throttle position is greater than 41.1 percent. |
• | The engine speed is between 2,400-3,008 RPM. |
• | The transmission output speed is greater than 704 RPM. |
• | The engine torque is greater than 50 N·m (68 lb ft). |
Condition 2:
• | The commanded gear is 4th for greater than 0.5 seconds. |
• | The accelerator pedal position is greater than 15 percent. |
• | The engine speed is 1,696-4,992 RPM. |
• | The transmission output speed is greater than 1,696 RPM. |
• | The engine torque is greater than 50 N·m (68 lb ft). |
• | The TCC is commanded ON. |
Conditions for Setting the DTC
DTC P0752 sets if the following conditions occur two times.
Condition 1:
The TCC slip speed is between -711 to 350 RPM for 0.6 seconds.
Condition 2:
The TCC slip speed is between 666 to 1,000 RPM for 5.0 seconds.
Action Taken When the DTC Sets
• | The TCM flashes the sport mode lamp and sends a MIL
request to the ECM on the second consecutive drive trip that the diagnostic
runs and fails. The ECM then illuminates the MIL. |
• | The ECM records the operating conditions in the Freeze Frame at
the time of the MIL request from the TCM. |
• | The transmission operates in the default mode (maximum line pressure,
command 4th gear, inhibit TCC, freeze shift adapts). |
Conditions For Clearing the MIL/DTC
• | The ECM turns off the MIL after three consecutive drive trips
during which the TCM sends no MIL request. |
• | A History DTC clears after forty consecutive warm-up cycles, if
no failures are present by this diagnostic or any other emission related diagnostic. |
• | The scan tool clears the MIL/DTC. |
• | The TCM cancels the DTC default mode actions when the
ignition switch is Off long enough in order to power down the TCM. |
Diagnostic Aids
• | Verify that the transmission meets the specifications in the
Shift Speed
table. |
• | Other internal transmission failures may cause more than one shift
to occur. |
Refer to
Shift Solenoid Valve State and Gear Ratio
.
Test Description
The number below refers to the step number on the diagnostic table.
-
This step tests
that the TCM commanded all shifts, that all shift solenoid valves responded
correctly, but that all the shifts did not occur.
Step
| Action
| Value(s)
| Yes
| No
|
1
| Did you perform
Powertrain On Board Diagnostic (OBD) System Check - Automatic Transmission
?
| --
|
Go to step 2
| Go to
Powertrain On Board Diagnostic (OBD) System Check - Automatic Transmission
|
2
|
- Install the Scan Tool
.
- Turn ON the ignition with the engine OFF.
Important: Record the Failure Records before clearing the DTCs. Using the Clear
Info function erases the Failure Records from the ECM and the TCM.
- Record the DTC Freeze Frame and Failure Records.
- Clear the DTC.
- Drive the vehicle in D range, under the following condition:
Accelerate the vehicle, ensuring that the TCM commands 1st, 2nd, 3rd
and 4th gears.
Did you detect a 2-2-3-3 shift pattern?
| --
|
Go to Step 3
| Go to Diagnostic Aids
|
3
|
- Inspect the 1-2/3-4 shift circuit for the following
conditions:
• | 1-2/3-4 Shift Solenoid Valve stuck ON |
• | Damaged 1-2/3-4 Shift Solenoid Valve O-ring |
• | 1-2 and 3-4 shift valve stuck in the released position |
- Repair the circuit. Refer to
Transmission Overhaul
in the 4L30-E Section of the Transmission
Unit Repair.
Did you find and correct the condition?
| --
|
Go to Step 4
| --
|
4
| Perform the following procedure in order to verify the
repair:
- Clear the DTCs.
- For condition 1, drive the vehicle in D range and ensure the following
conditions are met:
• | The accelerator pedal position is at least 10%. |
• | The TCM has commanded 1st gear. |
• | The engine speed is 992-2,400 RPM. |
• | The transmission output speed is greater than 192 RPM. |
• | The engine torque is greater than 50 N·m (68 lb ft). |
• | The TCC slip speed is 450-1,500 RPM for 1 second. |
- For condition 2, drive the vehicle in D and ensure the following
conditions are met:
• | The accelerator pedal position is at least 10%. |
• | The TCM has commanded 4th gear. |
• | The engine speed is 1996-3488 RPM. |
• | The transmission output speed is greater than 2400 RPM. |
• | The engine torque is greater than 50 N·m (68 lb ft). |
• | The TCC slip speed is -32 to +32 RPM for 3 seconds. |
Did the transmission shift through all drive ranges as commanded by
the TCM?
| --
| System OK
|
Go to Step 1
|