I have retrieved code 44 from OD flashlight, which points to an issue with the “transmission rear output shaft speed sensor”. The car has A540H transmission. Where is this speed sensor located? How many speed sensors does this transmission have?
This vehicle has two Speed Sensors. The Front Speed Sensor and the Rear Speed Sensor. The No. 1 Vehicle Speed Sensor is located on top of the transaxle. The No. 2 Speed Sensor is Located at the rear of the transaxle.
The front speed sensor detects vehicle speed based on ring gear RPM. The Rear speed sensor detects rear wheel speed based on transfer drive gear RPM. I have provided testing procedures for both sensors.
Testing the No. 1 Vehicle Speed Sensor (VSS)
- Disconnect electrical connector from No. 1 VSS, located on top of the transaxle. See Figure. Connect positive battery lead to terminal No. 1 and negative to terminal No. 2. Connect positive lead of voltmeter to terminal No. 3 and negative to terminal No. 2. See Fig 1.
- Raise and support one vehicle front wheel. Rotate wheel and monitor voltmeter. Ensure voltage changes from zero to 11 volts. Voltage should change 4 times per each revolution of speed sensor shaft. Replace speed sensor if voltage does not change as specified.
Testing the No. 2 Vehicle Speed Sensor (VSS)
- Ensure ignition is off. Access ECT ECU. See Figure Above for location. Backprobing ECT ECU harness connector with ohmmeter, measure resistance between terminal RR+ and terminal RR-. See Figure below. Resistance should be 560-680 ohms. If resistance is within specification, replace ECT ECU. If resistance is not within specification, go to next step.
- Remove rear speed sensor from transaxle. Measure resistance between sensor terminals. Resistance should be 560-680 ohms. If resistance is not specified, replace sensor. If resistance is specified, check and repair circuits between sensor and ECT ECU.
- Check voltage between sensor terminals when a magnet is put close to tip of sensor. If a low intermittent voltage is generated, sensor is okay. If no voltage is generated, replace speed sensor.
Toyota Code 44 – Deceleration Sensor Circuit
Code 44 Description
This sensor detects deceleration on the vehicle. The sensor signal is used in ABS control. If the sensor functions abnormally, the ABS warning light comes on but still operates.
Hello, Thank you very much.
It is very appreciating to learn that this vehicle has two speed sensors. I am quite clear with the No. 1 Vehicle speed sensor i.e. the one with gear wheel at the top.
However, when you say “The No. 2 Speed Sensor is Located and the rear of the transaxle”, I get a bit confused, because on my vehicle (1997 RAV4 with transmission A540H 02A), what appears to be the No.2 speed sensor is located almost next to the No.1 speed sensor. Is this what you mean?
Could you also help clarify the following;
1. Vehicle speed sensor
2. Front speed sensor
3. Rear speed sensor
4. No. 1 vehicle speed sensor
5. No. 2 vehicle speed sensor.
Those terms cause some confusion as they are used in repair manuals and other related technical information.
The No. 1 VSS is the Front Speed Sensor. The No. 2 VSS is the Rear Speed Sensor.
Yes
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