Massey Ferguson 105.04 – Engine Control Unit (ECU) / EEM3 or EEM4: Inlet Manifold Temperature Signal Voltage Low

The voltage signal returning from the intake manifold air temperature sensor to the controller has dropped below the normal operating range (typically below 0.1 volts). This condition almost always indicates a short circuit to ground in the sensor wiring harness or a complete internal failure of the sensor itself.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 8650
• 8660
• 8670
• 8680
• 8690
• 6485
• 7495

1. 1

   Verify if other sensor codes are active, as opens and shorts in the shared engine harness can cause multiple fault codes simultaneously

2. 2

   Inspect the wiring harness between the intake manifold temperature sensor and the Engine ECU for chafing, melted wires, or a signal circuit shorted to ground

3. 3

   Unplug the sensor, turn the key ON, and measure the voltage at the harness connector between the 5V reference supply pin and the ground pin (should read exactly 5Vdc)

4. 4

   Measure the resistance across the sensor pins. Resistance should decrease as it warms up; a reading of zero indicates a dead short and internal sensor failure

1. 1

   Power Down

   Turn off the tractor and disconnect the battery terminals before connecting or disconnecting the ECU vehicle connector to prevent sparking and pin damage.

2. 2

   Locate the Sensor

   Locate the Intake Manifold Temperature Sensor on the engine's intake manifold. Note: On many Sisu engines, this temperature sensor is integrated directly into the Boost Pressure Sensor (T-MAP sensor).

3. 3

   Repair Wiring (If Applicable)

   If the diagnostic checks revealed a short to ground in the harness, repair the damaged wire or replace the pigtail connector.

4. 4

   Replace the Sensor

   If the wiring is intact and the sensor failed the resistance test, unbolt the faulty sensor from the manifold, install the new sensor, and reconnect the harness.

5. 5

   Clear Codes

   Reconnect the battery, turn the key ON, and use a diagnostic tool (like the AGCO EDT) to clear the inactive 000105.04 fault code.