P011B

2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P011B: Engine Coolant Temperature / Intake Air Temperature Correlation

DTC P011B - Engine Coolant Temperature / Intake Air Temperature Correlation

DESCRIPTION

The ECM calculates the difference between the readings of the coolant temperature sensor and intake air temperature sensor. If the difference is greater than 20°C (36°F), the ECM will judge this as a malfunction and will set this DTC.









HINT:
- Waiting is required to prevent the temperature of the engine from affecting the readings. If the engine has been operated recently, it will not be possible to accurately compare the readings.
- For diagnosis, in order to duplicate the detection conditions of the DTC, it is necessary to park the vehicle for 7 hours. Parking the vehicle for 7 hours ensures that the actual temperature of the ECT and IAT are very similar. When the vehicle has been parked for less than 7 hours, differences in the readings may exist, this does not necessarily indicate a fault.

MONITOR DESCRIPTION

The ECM monitors the difference between the Engine Coolant Temperature (ECT) and the Intake Air Temperature (IAT) when the engine is started cold to detect the engine temperature accurately. The monitor runs when the engine started cold after 7 hours or more have elapsed since the engine was stopped (ignition switch turned off) on the previous trip. If the difference between the ECT and the IAT on a cold start exceeds 20°C (36°F), the ECM interprets this as a malfunction in the ECT sensor circuit and IAT sensor circuit, and sets the DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





INSPECTION PROCEDURE

PROCEDURE

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION P011B)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Code.
(e) Read the DTCs.
Result:





HINT: If any DTCs other than P011B are output, troubleshoot those DTCs first.

B -- GO TO DTC CHART
A -- Continue to next step.
2. READ VALUE USING TECHSTREAM (INTAKE AIR TEMPERATURE)
(a) Leave the vehicle for 7 hours or more.
HINT: It is necessary to leave the vehicle for 7 hours or more to allow conditions similar to the DTC detection conditions.
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch to the ON position.
(d) Turn the tester ON.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Intake Air.
(f) Read the value displayed on the tester.
OK:
The intake air temperature and the outside air temperature are within 10°C (50°F) of each other.
HINT: Temperature readings on the vehicle's outside temperature gauge (if equipped) are not suitable for comparing to the IAT reading. The outside temperature gauge has a significant delay built in to prevent temperature swings from being displayed on its display. Use an accurate thermometer to determine the outside air temperature.

NG -- REPLACE MASS AIR FLOW METER
OK -- Continue to next step.
3. READ VALUE USING TECHSTREAM (COOLANT TEMPERATURE)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
OK:
The coolant temperature and the outside air temperature are within 10°C (50°F) of each other.
HINT: If the result is not as specified, check if there are heat sources such as a block heater in the engine compartment.

NG -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR
OK -- REPLACE ECM