- DTC judgment completed
- System normal
| Last Modified: 07-31-2024 | 6.11:8.1.0 | Doc ID: RM100000001GJ5V |
| Model Year Start: 2020 | Model: Corolla | Prod Date Range: [01/2019 - 04/2020] |
| Title: 2ZR-FXE (ENGINE CONTROL): SFI SYSTEM: P012800,P012807; Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature); 2020 MY Corolla Corolla HV [01/2019 - 04/2020] | ||
|
DTC |
P012800 |
Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) |
|
DTC |
P012807 |
Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) Mechanical Failure |
DESCRIPTION
The ECM uses the engine coolant temperature sensor, installed to the water outlet, and the No. 2 engine coolant temperature sensor, installed to the radiator pipe assembly, to monitor the operation of the thermostat.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
MIL |
Memory |
Note |
|---|---|---|---|---|---|---|
|
P012800 |
Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) |
All of the following conditions are met for 5 seconds or more (2 trip detection logic):
|
|
Comes on |
DTC stored |
|
|
P012807 |
Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) Mechanical Failure |
All of the following conditions are met for 30 seconds or more (2 trip detection logic):
|
|
Comes on |
DTC stored |
|
MONITOR DESCRIPTION
P012800: Judgment by Simulated Engine Coolant Temperature
The ECM estimates the engine coolant temperature based on the starting temperature, engine load, and engine speed. The ECM then compares the estimated temperature with the actual engine coolant temperature. When the estimated engine coolant temperature reaches 75°C (167°F), the ECM checks the actual engine coolant temperature. If the actual engine coolant temperature is less than 75°C (167°F), the ECM interprets this as a malfunction of the thermostat or in the engine cooling system, illuminate the MIL and stores this DTC.
P012807: Judgment by Engine Coolant Temperature and No. 2 Engine Coolant Temperature Changes
When the engine coolant temperature is less than 75°C (167°F) and the water inlet housing with water pump sub-assembly is operating, if the rate of change and detected temperature of the engine coolant temperature sensor and No. 2 engine coolant temperature sensor differ by less than 0.1°C/sec. and 6.6°C respectively for a certain amount of time, the ECM will determine that the thermostat is stuck open, illuminate the MIL and store a DTC.
MONITOR STRATEGY
|
Related DTCs |
P0128: Coolant thermostat (judgment by simulated engine coolant temperature) P0128: Coolant thermostat (judgment by engine coolant temperature and No. 2 engine coolant temperature changes) |
|
Required Sensors/Components (Main) |
Thermostat Engine coolant temperature sensor |
|
Required Sensors/Components (Related) |
Intake air temperature sensor No. 2 engine coolant temperature sensor |
|
Frequency of Operation |
Once per driving cycle |
|
Duration |
100 seconds: Judgment by simulated engine coolant temperature -: Judgment by engine coolant temperature and No. 2 engine coolant temperature changes |
|
MIL Operation |
2 driving cycles |
|
Sequence of Operation |
None |
TYPICAL ENABLING CONDITIONS
All
|
Monitor runs whenever the following DTCs are not stored |
P0010 (Camshaft timing oil control valve) P0011 (VVT system - advance) P0012 (VVT system - retard) P0016 (VVT system - misalignment) P0031, P0032, P101D (Air fuel ratio sensor heater) P0101, P0102, P0103 (Mass air flow meter) P0107, P0108 (Manifold absolute pressure) P0111, P0112, P0113 (Intake air temperature sensor) P0116, P0117, P0118 (Engine coolant temperature sensor) P011B (Engine coolant temperature/intake air temperature correlation) P0121, P0122, P0123, P0222, P0223, P2135 (Throttle position sensor) P014C, P014D, P015A, P015B, P2195, P2196, P2237, P2238, P2239, P2252, P2253 (Air fuel ratio sensor) P0171, P0172 (Fuel system) P0300 - P0304 (Misfire) P0335 (Crankshaft position sensor) P0340, P0342, P0343 (Camshaft position sensor) P0351 - P0354 (Igniter) P0400 (EGR system) P0401 (EGR system (closed)) P0403 (EGR control circuit) P059F, P05A0, P05A2, P05A3, P05A4, P05A5, P05B2, P05B3, P05B4, U0284, U1293 (Active grille air shutter) P219A, P219C, P219D, P219E, P219F (Air-fuel ratio imbalance) |
Judgment by Simulated Engine Coolant Temperature
|
Auxiliary battery voltage |
11 V or higher |
|
Either of the following conditions is met |
1 or 2 |
|
1. All of the following conditions are met |
- |
|
Engine coolant temperature at engine start - Intake air temperature at engine start |
-15 to 7°C (-27 to 12.6°F) |
|
Engine coolant temperature at engine start |
-10 to 56°C (14 to 133°F) |
|
Intake air temperature at engine start |
-10 to 56°C (14 to 133°F) |
|
2. All of the following conditions are met |
- |
|
Engine coolant temperature at engine start - Intake air temperature at engine start |
Higher than 7°C (12.6°F) |
|
Engine coolant temperature at engine start |
56°C (133°F) or less |
|
Intake air temperature at engine start |
-10°C (14°F) or higher |
|
Accumulated time that vehicle speed is 128 km/h (80 mph) or more |
Less than 20 seconds |
Judgment by Engine Coolant Temperature and No. 2 Engine Coolant Temperature Changes
|
Auxiliary battery voltage |
11 V or higher |
|
Engine coolant temperature at first engine start |
-10°C (14°F) or higher |
|
Target engine coolant flow by engine water pump |
1.5 L/min or higher |
|
Engine coolant temperature sensor malfunction (P0117, P0118) |
Not detected |
|
No. 2 engine coolant temperature sensor malfunction (P00B3, P00B4) |
Not detected |
TYPICAL MALFUNCTION THRESHOLDS
Judgment by Simulated Engine Coolant Temperature
|
Duration that both of the following conditions are met |
5 seconds or more |
|
Estimated engine coolant temperature |
75°C (167°F) or higher |
|
Engine coolant temperature sensor output |
Less than 75°C (167°F) |
Judgment by Engine Coolant Temperature and No. 2 Engine Coolant Temperature Changes
|
Engine coolant temperature change speed |
Less than -0.4°C/sec (31°F/sec), or higher than 0.15°C/sec (32.27°F/sec) |
|
Engine coolant temperature |
Less than 75°C (167°F) |
|
Grade of engine coolant temperature - No. 2 engine coolant temperature |
Higher than -0.1°C/sec (-0.18°F/sec), and less than 0.1°C/sec (0.18°F/sec) |
|
Absolute engine coolant temperature - No. 2 engine coolant temperature |
Less than 6.6°C (11.8°F) |
CONFIRMATION DRIVING PATTERN
HINT:
-
After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
Click here
![2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; 2ZR-FXE (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR](/t3Portal/stylegraphics/info.gif)
-
When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
Click here
- Turn the power switch off and leave the vehicle for several hours.
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG) [A].
- Turn the Techstream on.
- Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature and Intake Air Temperature.
- Check that the value of the Data List item Coolant Temperature is 56°C (133°F) or less and the value of the Data List item Intake Air Temperature is between 0 and 35°C (32 and 95°F).
-
Put the engine in Inspection Mode (Maintenance Mode).
Click here
- Start the engine.
- Set the heater control to MAX HOT with fresh air mode selected and turn the A/C off.
-
With the engine running, drive the vehicle at 80 km/h (50 mph) for 15 minutes [B].
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
HINT:
If the engine stops, further depress the accelerator pedal to restart the engine.
-
After the value of the Data List item Coolant Temperature stabilizes, check that it is 75°C (167°F) or higher.
HINT:
If the value of the Data List item Coolant Temperature is less than 75°C (167°F) while driving the vehicle at 80 km/h (50 mph), inspect the cooling system and thermostat.
- Enter the following menus: Powertrain / Engine / Trouble Codes [C].
-
Read the pending DTCs.
HINT:
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
- Enter the following menus: Powertrain / Engine / Utility / All Readiness.
- Input the DTC: P012800, P012807.
-
Check the DTC judgment result.
Techstream Display
Description
NORMAL
ABNORMAL
- DTC judgment completed
- System abnormal
INCOMPLETE
- DTC judgment not completed
- Perform driving pattern after confirming DTC enabling conditions
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 is INCOMPLETE, let the engine cool down (engine coolant temperature is 56°C (133°F) or less), and then perform steps [A] and [C]: Normal judgment procedure.
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
- When clearing the permanent DTCs, do not disconnect the cable from the auxiliary battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.
CAUTION / NOTICE / HINT
HINT:
- When this DTC is output, check the engine coolant temperature using the Techstream. Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature. If the value of Coolant Temperature is lower than the actual engine coolant temperature, the engine coolant temperature sensor circuit may be malfunctioning. In this case, check the wire harnesses and connectors (and their connection condition) between the ECM and the engine coolant temperature sensor first.
- Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
|
1. |
CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P012800 OR P012807) |
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTCs.
Powertrain > Engine > Trouble Codes
|
Result |
Proceed to |
|---|---|
|
DTC P012800 or P012807 is output |
A |
|
DTC P012800, P012807 and other DTCs are output |
B |
HINT:
If any DTCs other than P012800 or P012807 are output, troubleshoot those DTCs first.
| B |
|
|
|
2. |
CHECK COOLING SYSTEM |
(a) Check for defects in the cooling system that might cause the system to be excessively cold, such as abnormal cooling fan operation or any modifications.
| NG |
|
REPAIR OR REPLACE COOLING SYSTEM |
|
|
3. |
INSPECT WATER INLET WITH THERMOSTAT SUB-ASSEMBLY |
(a) Inspect the water inlet with thermostat sub-assembly (thermostat opening temperature).
Click here
| NG |
|
|
|
4. |
INSPECT ENGINE COOLANT TEMPERATURE SENSOR |
(a) Inspect the engine coolant temperature sensor.
Click here
HINT:
Perform "Inspection After Repair" after replacing the engine coolant temperature sensor.
Click here
| NG |
|
|
|
5. |
INSPECT NO. 2 ENGINE COOLANT TEMPERATURE SENSOR |
(a) Inspect the No. 2 engine coolant temperature sensor.
Click here
| OK |
|
| NG |
|
|
|