John Deere 105 – Engine Control Unit (ECU): Intake Manifold Mixed Air Temp Sensor Is High / Intake Manifold Air Temperature Extremely High

This code is logged when the intake manifold air temperature signal indicates a temperature significantly greater than the normal operating range (often exceeding 91°C / 196°F). In engines equipped with Exhaust Gas Recirculation (EGR), this code specifically indicates that the mixed air temperature in the EGR system has excessively exceeded expected levels. This condition will typically trigger engine protection protocols, resulting in limited engine power (derate) or a commanded engine shut-off to prevent overheating damage.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5065M
• 5075M
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5095M
• 5095MH
• 5105M
• 5015ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 5E Series
• 5M Series
• 6R Series
• 7R Series
• 8R Series
• 9RT Track Tractors
• 9470RT
• 9520RT
• 9570RT
• S-Series Combines
• S660
• S670
• W-Series Combines
• T-Series Combines
• 7760 Cotton Pickers
• Forage Harvesters
• Skidders
• 640G
• 648G
• Loaders
• Excavators
• 9R Tractors
• 6000-series Tractors
• 1400-series Combines
• 1500-series Combines
• Compact Track Loaders
• 317G
• 333G

1. 1

   Check the engine coolant level and inspect the radiator, charge air cooler, and front grilles for dirt, chaff, or debris buildup that could restrict airflow.

2. 2

   Ensure the wiring harness is securely connected to the intake manifold air temperature sensor and inspect for chafing, breaks, or short circuits.

3. 3

   Inspect the EGR valve and cooler for clogging, operational faults, or sticking, as excessively hot exhaust gases mixing into the intake can trigger this code.

1. 1

   Clean Coolers

   Blow out the radiator and charge air cooler with compressed air to ensure maximum cooling efficiency.

2. 2

   Top Up Fluids

   Fill the coolant to the appropriate level using the specified John Deere Cool-Gard coolant.

3. 3

   Repair Wiring

   If the harness inspection revealed damage, repair the broken wires or replace the sensor pigtail connector.

4. 4

   Replace Sensor

   If the wiring is intact, the coolers are clean, and the code remains active (or the sensor reading is erratic on a diagnostic scanner), replace the Intake Manifold Air Temperature Sensor.

5. 5

   Service EGR

   If replacing the sensor does not clear the derate, the EGR valve may be failing to regulate exhaust gas properly. Remove and clean the EGR valve, or replace it if it is mechanically bound or electrically failed.

6. 6

   Clear Codes

   Clear the ECU codes using Service ADVISOR or a compatible diagnostic tool and test run the machine under load to verify the repair.