Case IH 19899 – Engine ECU / SCR Controller: High pressure intercooler outlet pressure signal failure

Indicates a failure in the signal from the sensor monitoring air pressure exiting the high-pressure intercooler. Often accompanied or superseded by related voltage-specific codes, such as DTC 19900 (voltage higher than expected) or DTC 19901 (voltage lower than expected).

• Tier 4b
• 240 Series Axial-Flow Combines

1. 1

   Connect the Case IH Electronic Service Tool (EST) to retrieve active DTCs and confirm if the signal failure is high voltage (19900) or low voltage (19901)

2. 2

   Visually inspect the high pressure intercooler outlet pressure sensor and wiring harness for chafing, melting, or physical damage

3. 3

   Disconnect the sensor and check the pins for corrosion, moisture, or pushed-back terminals

4. 4

   Back-probe the sensor connector to verify correct reference voltage and ground from the Engine ECU, and check the signal return wire for continuity

1. 1

   Power down machine

   Power down the machine and turn the battery disconnect switch to the OFF position.

2. 2

   Locate sensor

   Locate the high pressure intercooler outlet pressure sensor on the engine's intake/intercooler piping.

3. 3

   Disconnect sensor

   Disconnect the sensor's electrical connector.

4. 4

   Repair wiring harness

   If the diagnostic checks reveal a wiring fault (e.g., a short or open circuit in the harness), repair the affected section of the wiring harness.

5. 5

   Remove faulty sensor

   If the wiring and reference voltage test good but the signal failure persists, the sensor itself has failed internally. Remove the faulty sensor.

6. 6

   Install new sensor

   Install the new high pressure intercooler outlet pressure sensor and torque to OEM specifications.

7. 7

   Reconnect harness

   Reconnect the electrical harness.

8. 8

   Verify repair

   Turn the battery disconnect switch back ON, connect the EST, clear the inactive fault codes, and run the engine to verify that code 19899 does not return.