Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Vehicle speed sensor ”a” / Circuit description
Toyota Corolla (E120): Circuit description
The vehicle equipped with abs detects a vehicle speed using the stability control ecu and wheel speed sensor. This sensor monitors a wheel rotation speed and sends the signal to the ecu.
The stability control ecu converts these wheel speed signals into a 4–pulse signal and outputs it to the ecm via the combination meter.
The ecm determines the vehicle speed based on the frequency of these pulse signals.
In the vehicle without abs, the no. 1 Vehicle speed sensor outputs a 4–pulse signal for every revolution of the rotor shaft, which is rotated by the transmission output shaft via the driven gear. After this signal is converted into a more precise rectangular waveform by the waveform shaping circuit inside the combination meter, it is then transmitted to the ecm. The ecm determines the vehicle speed based on the frequency of these pulse signal.
W/ abs:
W/o abs:
Monitor description
Equipped with abs:
the ecm assumes that the vehicle is driven when the rpm of the transmission counter gear indicates more than 300 rpm and it has been over 30 seconds since the park/neutral position switch was turned off. If there is no signal from the vehicle speed sensor with these conditions satisfied, the ecm concludes that there is a fault in the vehicle speed sensor. The ecm will turn on the mil and a dtc is set.
Not equipped with abs:
the ecm assumes that the vehicle is driven when the park/neutral position switch is off and it has been over 4 seconds since the actual vehicle speed was 9 km/h or more.
If there is no signal from the vehicle speed sensor with these conditions satisfied, the ecm concludes that there is a fault in the vehicle speed sensor. The ecm will turn on the mil and a dtc is set.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Wiring diagram
Other materials:
On–vehicle inspection
1. Inspect speedometer
check the operation.
Using a speedometer tester, inspect the speedometer fro allowable
indication error and check
the operation of the odometer.
Reference:
Notice:
tire wear and tire over or under inflation will increase the indication error.
...
How to proceed with troubleshooting
The hand–held tester can be used at step 4, 6, 8 and 9.
1 Vehicle brought to workshop
2 Customer problem analysis
3 Warning light check
4 The dtcs check (present and past dtcs)
5 The dtcs chart
6 Circuit inspection
7 Repair
8 Clear the dtcs (present and past dtcs)
9 The dt ...
When using a child
restraint system
■ When installing a child
restraint system to a front
passenger seat
For the safety of a child, install a
child restraint system to a rear
seat. When installing a child
restraint system to a front passenger
seat is unavoidable,
adjust the seat as follows and
install the child restraint system:
M ...