Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000YSPM
Model Year Start: 2017 Model: Sienna Prod Date Range: [08/2016 - 08/2018]
Title: 2GR-FKS (ENGINE CONTROL): SFI SYSTEM: P012800; Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature); 2017 - 2018 MY Sienna [08/2016 - 08/2018]

DTC

P012800

Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

DESCRIPTION

This DTC is stored when the engine coolant temperature does not reach 75°C (167°F) despite sufficient engine warm-up time having elapsed.

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):

  1. Cold start.
  2. The engine is warmed up.
  3. The engine coolant temperature is less than 75°C (167°F).
  • Water inlet with thermostat sub-assembly
  • Engine cooling system
  • Engine coolant temperature sensor
  • ECM

Comes on

DTC stored
  • SAE Code: P0128
  • DTC for Mexico Models: Does not apply

MONITOR DESCRIPTION

The ECM estimates the engine coolant temperature based on the starting temperature, engine loads, and engine speeds. 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 in the thermostat or the engine cooling system and stores the DTC.

MONITOR STRATEGY

Related DTCs

P0128: Coolant thermostat

Required Sensors/Components (Main)

Thermostat

Engine coolant temperature sensor

Required Sensors/Components (Related)

Intake air temperature sensor (for mass air flow meter)

Vehicle speed sensor

Frequency of Operation

Once per driving cycle

Duration

950 seconds

MIL Operation

2 driving cycles

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored

P0010, P0020 (VVT oil control solenoid bank 1, 2)

P0011, P0021 (VVT system bank 1, 2 - advance)

P0012, P0022 (VVT system bank 1, 2 - retard)

P0013, P0023 (Exhaust VVT oil control solenoid bank 1, 2)

P0014, P0024 (Exhaust VVT system bank 1, 2 - advance)

P0015, P0025 (Exhaust VVT system bank 1, 2 - retard)

P0016, P0018 (VVT system bank 1, 2 - misalignment)

P0017, P0019 (Exhaust VVT system bank 1, 2 - misalignment)

P0031, P0032, P0051, P0052, P101D, P103D (Air fuel ratio sensor heater)

P0087, P0088, P0191, P0192, P0193 (Fuel pressure sensor (for high pressure side))

P0101, P0102, P0103 (Mass air flow meter)

P0111, P0112, P0113 (Intake air temperature sensor)

P0116, P0117, P0118 (Engine coolant temperature sensor)

P011B (Engine coolant temperature/intake air temperature sensor correlation)

P0121, P0122, P0123, P0222, P0223, P2135 (Throttle position sensor)

P014C, P014D, P014E, P014F, P015A, P015B, P015C, P015D, P2195, P2196, P2197, P2198, P2237, P2238, P2239, P2240, P2241, P2242, P2252, P2253, P2255, P2256 (Air fuel ratio sensor)

P0171, P0172, P0174, P0175 (Fuel system)

P0201, P0202, P0203, P0204, P0205, P0206, P062D, P21CF, P21D0, P21D1, P21D2, P21D3, P21D4 (Fuel injector)

P0300 - P0306 (Misfire)

P0335, P0337, P0338 (Crankshaft position sensor)

P0340, P0342, P0343, P0345, P0347, P0348 (VVT sensor)

P0365, P0367, P0368, P0390, P0392, P0393 (Exhaust VVT sensor)

P0351 - P0356 (Igniter)

P0500 (Vehicle speed sensor)

P107B, P107C, P107D (Fuel pressure sensor (for low pressure side))

P11EA, P11EB, P11EC, P11ED, P11EE, P11EF, P11F0, P11F1, P219A, P219B P219C, P219D, P219E, P219F, P21A0, P21A1 (Air-fuel ratio imbalance)

P1235 (High pressure fuel pump circuit)

Battery voltage

11 V or higher

Either of the following conditions is met

1 or 2

1. All of the following conditions are met

(a), (b) and (c)

(a) Engine coolant temperature at engine start - Intake air temperature (for mass air flow meter) at engine start

-15 to 7°C (-27 to 12.6°F)

(b) Engine coolant temperature at engine start

-10 to 56°C (14 to 133°F)

(c) Intake air temperature (for mass air flow meter) at engine start

-10 to 56°C (14 to 133°F)

2. All of the following conditions are met

(d), (e) and (f)

(d) Engine coolant temperature at engine start - Intake air temperature (for mass air flow meter) at engine start

Higher than 7°C (12.6°F)

(e) Engine coolant temperature at engine start

56°C (133°F) or less

(f) Intake air temperature (for mass air flow meter) at engine start

-10°C (14°F) or higher

Accumulated time at vehicle speed of 128 km/h (80 mph) or more

Less than 20 seconds

TYPICAL MALFUNCTION THRESHOLDS

Duration that both of the following conditions are met

5 seconds or more

(a) Estimated engine coolant temperature

75°C (167°F) or higher

(b) Engine coolant temperature sensor output

Less than 75°C (167°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 2017 - 2020 MY Sienna [08/2016 -        ]; 2GR-FKS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

  • When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.

    Click here 2017 - 2020 MY Sienna [08/2016 -        ]; 2GR-FKS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

  1. Stop the engine and allow it to soak.
  2. Connect the Techstream to the DLC3.
  3. Turn the ignition switch to ON and turn the Techstream on [A].
  4. Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature and Intake Air Temperature.
  5. Check that "Coolant Temperature" is 56°C (133°F) or less and "Intake Air Temperature" is between 0 and 35°C (32 and 95°F).
  6. Set the heater to MAX HOT with fresh air mode selected and turn the A/C off.
  7. Start the engine and drive the vehicle at 80 km/h (50 mph) or more for 20 minutes [B].

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

  8. After "Coolant Temperature" stabilizes, check that "Coolant Temperature" is 75°C (167°F) or higher.

    HINT:

    If "Coolant Temperature" is less than 75°C (167°F) while driving the vehicle at 80 km/h (50 mph), inspect the engine cooling system and thermostat.

  9. Enter the following menus: Powertrain / Engine / Trouble Codes [C].
  10. 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.
  11. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
  12. Input the DTC: P012800.
  13. Check the DTC judgment result.

    Techstream Display

    Description

    NORMAL
    • DTC judgment completed
    • System 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.
    • let the engine cool down (engine coolant temperature is 56°C (133°F) or less), and then perform steps [A] through [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 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 the DTC is output, check the engine coolant temperature using the Techstream. Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature. If the Coolant Temperature value 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 those connections) 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)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Trouble Codes.

(e) Read the DTCs.

Result

Proceed to

DTC P012800 is output

A

DTC P012800 and other DTCs are output

B

HINT:

If any DTCs other than P012800 are output, troubleshoot those DTCs first.

B

GO TO DTC CHART 2017 MY Sienna [08/2016 - 11/2017]; 2GR-FKS (ENGINE CONTROL): SFI SYSTEM: DIAGNOSTIC TROUBLE CODE CHART 2018 MY Sienna [11/2017 - 08/2018]; 2GR-FKS (ENGINE CONTROL): SFI SYSTEM: DIAGNOSTIC TROUBLE CODE CHART

A

2.

CHECK ENGINE COOLING SYSTEM

(a) Check for defects in the engine cooling system that might cause the system to be too cold, such as abnormal cooling fan operation or any modifications.

NG

REPAIR OR REPLACE ENGINE COOLING SYSTEM
OK

3.

INSPECT WATER INLET WITH THERMOSTAT SUB-ASSEMBLY

(a) Inspect the water inlet with thermostat sub-assembly (thermostat opening temperature).

Click here 2017 - 2020 MY Sienna [08/2016 -        ]; 2GR-FKS (COOLING): THERMOSTAT: INSPECTION

NG

REPLACE WATER INLET WITH THERMOSTAT SUB-ASSEMBLY

OK

4.

INSPECT ENGINE COOLANT TEMPERATURE SENSOR

(a) Inspect the engine coolant temperature sensor.

Click here 2017 - 2020 MY Sienna [08/2016 -        ]; 2GR-FKS (ENGINE CONTROL): ENGINE COOLANT TEMPERATURE SENSOR: INSPECTION

HINT:

Perform "Inspection After Repair" after replacing the engine coolant temperature sensor.

Click here 2017 MY Sienna [08/2016 - 11/2017]; 2GR-FKS (ENGINE CONTROL): SFI SYSTEM: INITIALIZATION 2018 - 2020 MY Sienna [11/2017 -        ]; 2GR-FKS (ENGINE CONTROL): SFI SYSTEM: INITIALIZATION

OK

REPLACE ECM

NG

REPLACE ENGINE COOLANT TEMPERATURE SENSOR