AC60E AUTOMATIC TRANSMISSION / TRANSAXLE AUTOMATIC TRANSMISSION SYSTEM(for 7GR-FKS) P28077F Pressure Control Solenoid "G" Actuator Stuck Off
DESCRIPTION
The ECM uses the vehicle speed signal and signals from the transmission revolution sensors (NT, SP2) to detect the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear).
The ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid valves, transmission valve body assembly or automatic transmission assembly (clutch, brake or gear etc.).
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory | Note |
|---|---|---|---|---|---|---|
| P28077F | Pressure Control Solenoid "G" Actuator Stuck Off | Either condition is met (2 trip detection logic):
·
The engine revs freely when a shift to 3rd or 5th gear is commanded. ·
The condition that 4th gear is engaged when a shift to 4th gear is commanded occurs twice, and one of the following conditions is met: -
When a shift to 1st gear is commanded, 3rd gear is engaged. -
When a shift to 2nd gear is commanded, 3rd gear is engaged. -
When a shift to 6th gear is commanded, 5th gear is engaged. |
·
Shift solenoid valve SL4 remains open or closed ·
Transmission valve body assembly is blocked ·
Automatic transmission assembly (clutch, brake or gear etc.) |
Comes on | DTC stored | SAE Code:
P2808 |
| Vehicle Condition | |||||
|---|---|---|---|---|---|
| Pattern 1 | Pattern 2 | Pattern 3 | Pattern 4 | ||
| Diagnostic Condition | Ignition switch is ON | ○ | ○ | ○ | ○ |
| Malfunction Condition | The engine revs freely when a shift to 3rd or 5th gear is commanded. | ○ | - | - | - |
| The following condition is met twice:
When a shift to 4th gear is commanded, 4th gear is engaged. |
- | ○ | ○ | ○ | |
| When a shift to 1st gear is commanded, 3rd gear is engaged. | - | ○ | - | - | |
| When a shift to 2nd gear is commanded, 3rd gear is engaged. | - | - | ○ | - | |
| When a shift to 6th gear is commanded, 5th gear is engaged. | - | - | - | ○ | |
| Duration | - | - | - | - | |
| Detection Logic | 2 trip detection logic | 2 trip detection logic | 2 trip detection logic | 2 trip detection logic | |
- HINT:
-
This DTC is stored when any of the above detection patterns are met.
MONITOR DESCRIPTION
The ECM commands gear shifts by turning the shift solenoid valves on and off. According to the input turbine speed and output shaft speed, the ECM detects the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear). When the gear commanded by the ECM and the actual gear are not the same, the ECM illuminates the MIL and stores the DTC.
CONFIRMATION DRIVING PATTERN
- CAUTION:
-
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
- HINT:
-
After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the GTS on.
Start the engine.
Perform the D Position Shift Test in Road Test.
Stop the vehicle.
Enter the following menus: Powertrain / Transmission / Utility / All Readiness.
Input the DTC: P28077F.
Check the DTC judgment result.
| GTS Display | Description |
|---|---|
| NORMAL | ·
DTC judgment completed ·
System normal |
| ABNORMAL | ·
DTC judgment completed ·
System abnormal |
| INCOMPLETE | ·
DTC judgment not completed ·
Perform driving pattern after confirming DTC enabling conditions |
| N/A | ·
Unable to perform DTC judgment ·
Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit |
- HINT:
- ·
If the judgment result shows NORMAL, the system is normal.
·If the judgment result shows ABNORMAL, the system has a malfunction.
·If the judgment result shows INCOMPLETE or N/A, perform the Confirmation Driving Pattern and check the DTC judgment result again.
CAUTION / NOTICE / HINT
- NOTICE:
-
Perform registration and/or initialization when parts related to the automatic transmission are replaced
PROCEDURE
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Transmission / Trouble Codes.
- Powertrain > Transmission > Trouble Codes
- 50001 373
Read the DTCs using the GTS.
- Result:
Result Proceed to Only DTC P28077F is output A P28077F and other DTCs are output B
- HINT:
-
If a solenoid is stuck off, DTCs for several solenoids including the malfunctioning solenoid will be detected.
A
B
- NOTICE:
-
This test should always be performed with at least 2 people.
Warm up the engine.
Turn the ignition switch off.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Transmission / Active Test / Control the Shift Position.
Perform the Active Test according to the display on the GTS.
- HINT:
-
Comparing the gear commanded by the Active Test with the actual gear enables confirmation of the problem.
- Powertrain > Transmission > Active Test
-
Tester Display Measurement Item Control Range Diagnostic Note Control the Shift Position Operates the shift solenoid valves to allow gears to be selected manually. 1st/2nd/3rd/4th/5th/6th
Start/StopCan be used to check the operation of the shift solenoid valves.
Up-shifts and down-shifts should be performed consecutively. A 10 second interval is required between gear changes.
Do not down-shift at high speeds. Doing so will damage the automatic transmission assembly.
[Vehicle Condition]50 km/h (31 mph) or less
- Powertrain > Transmission > Active Test
-
Tester Display Control the Shift Position - 50004 373 42009
- HINT:
- ·
This test can be conducted when the vehicle speed is 50 km/h (31 mph) or less.
·The 4th to 5th and 5th to 6th up-shift must be performed with the accelerator pedal released.
·The 6th to 5th and 5th to 4th down-shift must be performed with the accelerator pedal released.
·Do not operate the accelerator pedal for at least 2 seconds after shifting and do not shift successively.
·The gear commanded by the ECM is shown in the Data List / Shift Status display on the GTS.
Compare the ECM commanded gear and actual gear.
- Result:
Actual Gear during Malfunction ECM Commanded Gear Proceed to 1st 2nd 3rd 4th 5th 6th Shift solenoid valve SL1 Stuck ON 1st 2nd 3rd 4th 4th 4th A Stuck OFF N*1 N*1 N*1 N*1 5th 6th Shift solenoid valve SL2 Stuck ON 4th 4th 4th 4th 5th 6th B Stuck OFF 1st 2nd 3rd 1st N*1 N*1 Shift solenoid valve SL3 Stuck ON 2nd 2nd 3rd 4th 5th 6th C Stuck OFF 1st 1st 3rd 4th 5th N*1 Shift solenoid valve SL4 Stuck ON 3rd 3rd 3rd 4th 5th 5th D Stuck OFF 1st 2nd 1st 4th N*1 6th Shift solenoid valve SLT Stuck ON N*2 N*2 N*2 N*2 N*2 N*2 E Stuck OFF*3 1st 2nd 3rd 4th 5th 6th
- HINT:
- ·
*1: Neutral
·*2: If shift solenoid valve SLT is stuck on, the line pressure will be low. Therefore, the amount of torque that can be transmitted by each gear is lower than the normal limit. When the engine power exceeds this lowered limit, the engine speed will increase freely.
·*3: When shift solenoid valve SLT is stuck off, gear shifting is normal.
A
B
C
D
E
| *1 | Shift Solenoid Valve SL4 |
Remove shift solenoid valve SL4.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition 1 - 2 20°C (68°F) 5.0 to 5.6 Ω
Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.
- OK:
Measurement Condition Specified Condition ·Battery positive (+) with a 21 W bulb → Terminal 1
·Battery negative (-) → Terminal 2
Valve moves and makes an operating noise
- Result:
Proceed to OK NG
OK
NG
Check the transmission valve body assembly.
- OK:
There is no foreign matter on each valve and they operate smoothly.
- Result:
Proceed to OK NG
OK
NG