Drivetrain. Corolla. Zre142 Aze141
U341E Automatic Transmission Transaxle. Corolla. Zre142 Aze141
TYPICAL MALFUNCTION THRESHOLDS
CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0751)
INSPECT SHIFT SOLENOID VALVE S1
INSPECT TRANSMISSION VALVE BODY ASSEMBLY
DTC P0751 Shift Solenoid "A" Performance (Shift Solenoid Valve S1) |
SYSTEM DESCRIPTION
The ECM uses signals from the vehicle speed sensor and speed sensor NT to detect the actual gear position (1st, 2nd, 3rd or 4th gear).Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect the mechanical problems of the shift solenoid valves, the valve body or automatic transaxle (clutch, brake or gear etc.).
| DTC No. | DTC Detection Condition | Trouble Area |
| P0751 | The gear required by the ECM does not match the actual gear when driving (2-trip detection logic) |
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MONITOR DESCRIPTION
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". According to the input shaft revolution, intermediate (counter) shaft revolution and output shaft revolution, the ECM detects the actual gear position (1st, 2nd, 3rd or 4th gear position). When the gear position commanded by the ECM and the actual gear position are not same, the ECM illuminates the MIL and stores the DTC.MONITOR STRATEGY
| Related DTCs | P0751: Shift solenoid valve S1/OFF malfunction Shift solenoid valve S1/ON malfunction |
| Required sensors/Components | Shift solenoid valve S1, Speed sensor (NT), Speed sensor (SPD), Engine coolant temperature sensor (ECT) |
| Frequency of operation | Continuous |
| Duration | OFF malfunction (a): 0.85 seconds OFF malfunction (b): 0.8 seconds ON malfunction (a): 0.8 seconds ON malfunction (b): 0.8 seconds |
| MIL operation | 2 driving cycle |
| Sequence of operation | None |
TYPICAL ENABLING CONDITIONS
The following conditions are common to all OFF malfunctions and ON malfunctions.| The monitor will run whenever this DTC is not present. (Not circuit malfunction) | P0500 (Vehicle speed sensor circuit) P0115, P0117, P0118 (ECT sensor circuit) P0717 (Turbine speed sensor circuit) P0973, P0974 (Shift solenoid valve S1 circuit) P0976, P0977 (Shift solenoid valve S2 circuit) P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0604, P0606, P0607, P060A, P060D, P060E, P0657, P1607, P2102, P2103, P2111, P2112, P2118, P2119, P2135 (Electronic throttle control system) |
| ECT (Engine Coolant Temperature) | 60°C (140°F) or more |
| Time after shifting N to D | 4.5 seconds or more |
| Transmission shift position | D |
| Shift solenoid valve S1 circuit | No circuit malfunction |
| Shift solenoid valve S2 circuit | No circuit malfunction |
| ECT sensor circuit | No circuit malfunction |
| Electronic Throttle Control System (if applicable) | No circuit malfunction |
| Speed sensor (NT) circuit | No circuit malfunction |
| Speed sensor (SPD) circuit | No circuit malfunction |
| ECM gearshift command | 1st |
| Vehicle speed | 5.6 mph (9 km/h) or more and Less than 24.9 mph (40 km/h) |
| Throttle valve opening angle | 7.0 % or more and 4.0 % or more at engine speed of 1900 rpm (Conditions vary with engine speed) |
| ECM gearshift command | 4th |
| Last ECM selected gear | 3rd |
| ECM gearshift command | 4th |
| Last ECM selected gear | 3rd |
| ECM gearshift command | 4th |
| V current - V last V current: Vehicle speed at current ECM selected gear V last: Vehicle speed at last ECM selected gear | Less than 9.3 mph (15 km/h) |
| TH current - TH last TH current: Throttle valve opening angle at current ECM selected gear TH last: Throttle valve opening angle at last ECM selected gear | Less than 20 % |
| Vehicle speed (current) | Less than 52.8 mph (85 km/h) |
| Throttle valve opening angle (current) | Less than 35 % |
| Engine speed (current) | 3200 rpm or more |
TYPICAL MALFUNCTION THRESHOLDS
[OFF malfunction]
- Both of the following conditions met: OFF malfunctions (a) and (b)
2 detections are necessary per driving cycle.
1st detection: Temporary flag ON
2nd detection: Pending fault code ON
| Input speed/Output speed (NT/NO) NT: Input (turbine) speed NO: Internal counter shaft speed | 0.64 or more and less than 0.78 (Current) (This means actual gear is 4th) |
| Input speed/Output speed (NT/NO) | Changes as follows 0.95 or more and less than 1.09 (Last) (This means actual gear is 3rd) to 0.64 or more and less than 0.78 (Current) (This means actual gear is 4th) |
[ON malfunction]
- Both of the following conditions met: ON malfunctions (a) and (b)
| Input speed/Output speed (NT/NO) | No change as follows 0.95 or more and less than 1.09 (Last) (This means actual gear is 3rd) to 0.64 or more and less than 0.78 (Current) (This means actual gear is 4th) |
NE change
| 1100 rpm or more |
INSPECTION PROCEDURE
- NOTICE:
- Perform the universal trip to clear permanent DTCs (COROLLA_ZRE142 RM000000W770S5X.html).
- HINT:
- Using the Techstream to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.
| PERFORM ACTIVE TEST |
Warm up the engine.
Turn the ignition switch off.
Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn on the Techstream.
Select the item "Powertrain / Engine and ECT / Active Test".
According to the display on the Techstream, perform the "Active Test".
- HINT:
- While driving, the shift position can be forcibly changed with the Techstream.
- Comparing the shift position commanded by the Active Test with the actual shift position enables you to confirm the problem (COROLLA_ZRE142 RM000000O8L0N1X.html).
| Tester Display | Test Part | Control Range | Diagnostic Note |
| Control the Shift Position | [Test Details] Operate the shift solenoid valve and set the each shift position by yourself. [Vehicle Condition]
| 1st/2nd/3rd/4th | Possible to check the operation of the shift solenoid valves. |
- HINT:
- This test can be conducted when the vehicle speed is 50 km/h (31 mph) or less.
- The shift position commanded by the ECM is shown in the Data List/Shift Status display on the Techstream.
| 1.CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0751) |
Connect the Techstream to the DLC3.
Turn the ignition switch to ON and the Techstream main switch on.
Select the item "Powertrain / Engine and ECT / Trouble Codes".
Read the DTCs using the Techstream.
- Result:
Result Proceed to P0751 A P0751 and other DTCs B
- HINT:
- If any other codes besides "P0751" are output, perform the troubleshooting for those DTCs first.
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| A | |
| 2.INSPECT SHIFT SOLENOID VALVE S1 |
Remove the shift solenoid valve S1.
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Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Condition Specified Condition Solenoid Connector (S1) - Solenoid Body (S1) 20°C (68°F) 11 to 15 Ω
Connect the positive (+) lead to the terminal of the solenoid connector, and the negative (-) lead to the solenoid body.
- OK:
- The solenoid makes an operating sound.
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| OK | |
| 3.INSPECT TRANSMISSION VALVE BODY ASSEMBLY |
- OK:
- There are no foreign objects on each valve and they operate smoothly.
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| OK | ||
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