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DTC P011B-00: Engine coolant temperature/Intake air temperature correlation
 
 
 
 
CIRCUIT OPERATION
<Intake air temperature sensor>
  • Intake air temperature sensor is built into the mass airflow sensor.
  • Power is supplied by the ECM connector terminal number 76 to the mass airflow sensor connector terminal number 1.
  • The mass airflow sensor connector terminal number 3 is grounded through the ECM connector terminal number 98.
  • The sensor signal is inputted to the ECM connector terminal number 78 from the mass airflow sensor connector terminal number 2.
<Engine coolant temperature sensor>
  • A power voltage of 5 volts is applied to the engine coolant temperature sensor connector terminal number 1 from the ECM connector terminal number 38.
  • The power voltage is grounded to the ECM connector terminal number 28 from the engine coolant temperature sensor connector terminal number 2.
  • The engine coolant temperature sensor is a negative temperature coefficient type of resistor. It has the characteristic that when the engine coolant temperature rises the resistance decreases.
  • The engine coolant temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases.
 
 
TECHNICAL DESCRIPTION
<Intake air temperature sensor>
  • The intake air temperature sensor converts the intake air temperature into a voltage and inputs the voltage signal to the ECM.
<Engine coolant temperature sensor>
  • The engine coolant temperature sensor converts the engine coolant temperature to a voltage and outputs it.
  • The ECM checks whether this voltage is within a specified range.
 
 
DESCRIPTIONS OF MONITOR METHODS
Intake air temperature sensor output voltage does not change when specified go/stop operations are repeated.
 
 
MONITOR EXECUTION
Once per driving cycle.
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC set in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Engine coolant temperature sensor
  • Intake air temperature sensor
 
 
DTC SET CONDITIONS
Logic Flow Chart
 
 
Check Conditions
  • Power supply mode of electric motor switch is ON.
  • 12V battery positive voltage is 10 volts or higher.
  • ECM is woken up in 6 hours since the engine was stopped.
  • 2 seconds or more have elapsed after the above mentioned conditions have been met.
Judgment Criterion
  • The engine coolant temperature – intake air temperature is less than –35°C (–31°F) or higher than 32°C (90°F) when the power supply mode of electric motor switch is ON.
 
 
FAIL-SAFE AND BACKUP FUNCTION
None.
 
 
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 4 OBD- II DRIVE CYCLE.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • Engine coolant temperature sensor failed.
  • Engine coolant temperature sensor circuit harness damage or connector damage.
  • Intake air temperature sensor (built into the mass airflow sensor) failed.
  • Intake air temperature sensor circuit harness damage or connector damage.
  • ECM failed.
 
 
DIAGNOSIS
Required Special Tools:
  • MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
  • MB992745: V.C.I.-Lite main harness A
  • MB992747: V.C.I.-Lite USB cable short
  • MB992748: V.C.I.-Lite USB cable long
1.STEP 1. Using scan tool (M.U.T.-III SE), read the DTC.
Use scan tool (M.U.T.-III SE) to check and see if a DTC U060F-00 is set.
Q: Is DTC U060F-00 set?
Perform troubleshooting for the set DTC (Refer to DTC U060F-00: Lost Communication with Volume Air Flow Sensor DTC U060F-00: Lost Communication with Volume Air Flow Sensor). Then .
 
2.STEP 2. Test the OBD-II drive cycle.
After erasing the DTC, carry out test drive with the drive cycle pattern, and recheck the DTC.
(1) Use scan tool (M.U.T.-III SE) to erase the DTC.
(2) Carry out test drive with the drive cycle pattern (Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 4 OBD- II DRIVE CYCLE).
(3) Use scan tool (M.U.T.-III SE) to recheck the DTC.
Q: Is DTC P011B-00 set?
The inspection is complete.
 
3.STEP 3. Using scan tool (M.U.T.-III SE), check the data list.
Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 50: Air Temperature Sensor
Q: Is the check result normal?
Replace the mass airflow sensor (Refer to ENGINE, Intake and Exhaust – Air Cleaner AIR CLEANER REMOVAL AND INSTALLATION). Then
 
4.STEP 4. Using scan tool (M.U.T.-III SE), check the data list.
Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 60: Coolant (Water) Temperature Sensor
Q: Is the check result normal?
 
5.STEP 5. Check engine coolant temperature sensor itself.
Check engine coolant temperature sensor itself (Refer to ENGINE COOLANT TEMPERATURE SENSOR CHECK).
Q: Is the check result normal?
Replace the engine coolant temperature sensor (Refer to ENGINE, Engine Cooling – Water Hose and Water Pipe WATER HOSE AND WATER PIPE REMOVAL AND INSTALLATION). Then
 
6.STEP 6. Perform resistance measurement at engine coolant temperature sensor connector terminal number 2.
  • Disconnect connector, and measure at harness side.
  • Resistance between engine coolant temperature sensor connector terminal number 2 and ground.
OK: Continuity (2 ohms or less)
Q: Is the check result normal?
 
7.STEP 7. Check harness between engine coolant temperature sensor connector terminal number 2 and ECM connector terminal number 28.
Check ground line for open circuit and damage.
Q: Is the check result normal?
Repair or replace the connector, or repair the damaged harness wire.
 
8.STEP 8. Check harness between engine coolant temperature sensor connector terminal number 1 and ECM connector terminal number 38.
Check power supply line for short circuit and damage.
Q: Is the check result normal?
Repair or replace the connector, or repair the damaged harness wire.
 
9.STEP 9. Using scan tool (M.U.T.-III SE), check the data list.
Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 60: Coolant (Water) Temperature Sensor
Q: Is the check result normal?
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).
 
10.STEP 10. Test the OBD-II drive cycle.
After erasing the DTC, carry out test drive with the drive cycle pattern, and recheck the DTC.
(1) Use scan tool (M.U.T.-III SE) to erase the DTC.
(2) Carry out test drive with the drive cycle pattern (Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 4 OBD- II DRIVE CYCLE).
(3) Use scan tool (M.U.T.-III SE) to recheck the DTC.
Q: Is DTC P011B-00 set?
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).
The inspection is complete.