P0111 - Intake Air Temperature Sensor 1 Performance
Theory of Operation
The Intake Manifold Temperature (IMT) Sensor is located on the intake manifold on the Regular Cab. For the Cab and Chassis, it is a part of the Temperature/Pressure MAP Sensor. The IMT Sensor is used to measure the temperature of the air in the intake manifold. The Powertrain Control Module (PCM) supplies 5-Volts to the intake manifold temperature signal circuit. The PCM monitors the change in voltage caused by changes in the
resistance of the sensor to determine the intake manifold temperature. The MIL lamp is illuminated immediately when the diagnostic runs and fails. During this time the customer may notice periods of white smoke as well as the fan running more often. The MIL lamp is turned off once the diagnostic runs and passes in four consecutive drive cycles.
When Monitored and Set Conditions
When Monitored: This diagnostic runs continuously when the following conditions are met:
• With the ignition on.
• With the Engine running.
Set Conditions:
• The Powertrain Control Module (PCM) has detected the Intake Air Temperature (IAT) Sensor reads
differently than the Engine Coolant Temperature (ECT) Sensor with the ignition on and Engine off. With
the ignition on and Engine running the PCM does not read a change in value from the Intake Air
Temperature circuit over a calibrated amount of time.
Default Actions:
• The MIL is illuminated.
Possible Causes
AIR CLEANER BOX NOT SEALING PROPERLY TO THE AIR INLET TUBE
DIRT OR DEBRIS IN CHARGE AIR COOLING SYSTEM
TEMPERATURE/PRESSURE MAP SENSOR
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTCBased Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
1. OTHER DTCS
1. Ignition on, engine not running.
2. With the scan tool, read DTCs.
Are DTC P0112 or P0113 present?
Yes
• Repair those DTCs first.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
• Go To 2
2. CHECK THE CHARGE AIR COOLER AND SYSTEM FOR DIRT OR DEBRIS
1. Remove the hoses at the Charge Air Cooler and Turbo outlet and inspect the system for signs of excessive oil, dirt or debris.
Does the Charge Air Cooling system show signs of excessive dirt or debris?
Yes
• Clean the Charge Air Cooling system in accordance with the service information.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
• Go To 3
3. COMPARE THE INTAKE AIR TEMPERATURE CIRCUIT
1. After an eight hour cold soak, connect the scan tool and monitor intake air temperature, EGR orifice temperature, and engine coolant temperature.
NOTE: Make sure ambient air temperature is above -6.7°C (20°F) when performing this test.
NOTE: Make sure there is no external heat source, such as a block heater, operating during this test or within the eight hour cold soak.
Does the Intake Air Temperature circuit read differently from the other sensors?
Yes
• Replace the Temperature/Pressure MAP Sensor in accordance with the service information.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
• Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).