Toyota Corolla Repair Manual: Circuit description
Refer to dtc p0115
|
Dtc no. |
Dtc detection condition |
Trouble area |
| P0125 | If the engine coolant temperature (ect) was less than –6.6 °C (20 °F) when starting the engine, and 20 minutes after the engine start, the ect sensor still indicates below 20 °C (68 °F) |
|
| If the ect was between –6.6 °C (20 °F) and 10 °C (50 °F) when start, 5 minutes after the start, the ect sensor still indicates below 20 °C (68 °F) | ||
| If the ect was greater than 10 °C (50 °F) when starting the engine, and 2 minutes after the engine start, ect sensor still indicates below 20 °C (68 °F) |
Monitor description
The engine coolant temperature (ect) sensor is used to monitor the temperature of the engine coolant. The resistance of the sensor varies with the actual coolant temperature. The ecm applies a voltage to the sensor and the varying resistance of the sensor causes the signal voltage to vary. The ecm monitors the ect signal voltage after engine start–up. If, after sufficient time has passed, the sensor still reports that the engine is not warm enough for closed–loop fuel control, the ecm interprets this as a fault in the sensor or cooling system.
Example: the engine coolant temperature was 0 c (32 f) at engine start. After 5 minutes running time, the coolant temperature sensor still indicates that the engine is not warm enough to begin air–fuel ratio feedback control.
The ecm interprets this as a fault in the sensor or cooling system and will set a dtc.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Wiring diagram
Refer to dtc p0115
Insufficient coolant temperature
for closed loop fuel control
Dtc p0125 insufficient coolant temperature
for closed loop fuel control ...
Inspection procedure
Hint:
if dtcs p0115, p0116, p0117, p0118 and p0125 are output
simultaneously, the engine coolant temperature
sensor circuit may be open or short. Perform the troubleshooting of dtc
p0115, ...
Other materials:
Overhaul
1. Remove console panel upper
2. Remove console box carpet
3. Remove parking brake hole cover sub–assy
4. Remove console box sub–assy rear
5. Disconnect floor shift cable transmission control shift
Remove the cable end from the rod of the floor shift assembly.
Using a screw ...
Circuit description
The vehicle speed sensor circuit is sent to cruise control ecu assy as a
vehicle speed signal. For each rotation
of the shaft, the vehicle speed sensor sends a signal through the combination
meter assembly to the
cruise control ecu assy (see the following chart). The cruise control ecu assy
...
How to proceed with troubleshooting
1 Vehicle brought to workshop
2 Customer problem analysis
3 Check and clear dtc
4 Problem symptom confirmation
Symptom does not occur (go to
step 5)
5 Symptom simulation
6 Dtc check
7 Dtc chart
8 Problem symptoms table
9 Circuit inspection
10 Confirmation test
End
...