Case IH 492 – Engine Control Module (ECM) / ENG: Wastegate 2 voltage is too low

The engine control system has detected that the voltage signal in the turbocharger bypass control circuit (wastegate actuator 2) has dropped below the normal operating range, indicating an open circuit, a short circuit to ground, or a failed actuator solenoid.

• MX Magnum
• STX Steiger
• MX180
• MX200
• MX210
• MX220
• MX230
• MX240
• MX270
• 7230
• 7240
• 7250
• 8930
• 8940
• 8950
• STX275
• STX325
• 9310
• 9330
• 2166
• 2188
• 2366
• 2377
• 2388
• 8240
• 9240
• 821C Loader
• CX330 Excavator
• 2155
• 2555
• CPX420
• FLX3300B
• FLX3330B

1. 1

   Inspect the turbocharger wastegate actuator 2 and its wiring harness for obvious physical damage, melting, or disconnected plugs.

2. 2

   Check the engine wiring harness between the ECM and the wastegate actuator for an open circuit or a short circuit to ground.

3. 3

   Disconnect the actuator and ECM connectors to check for pushed-back pins, corrosion, or moisture intrusion.

4. 4

   Measure the resistance of the wastegate actuator solenoid to verify it is within OEM specifications (a dead short internally will pull the circuit voltage low).

1. 1

   Power Down

   Turn off the engine, remove the key, and disconnect the battery to prevent electrical spikes.

2. 2

   Isolate the Fault

   Disconnect the wiring harness at the wastegate actuator. Using a digital multimeter, check the continuity of the signal and ground wires back to the ECM.

3. 3

   Repair Wiring (If Applicable)

   If a short to ground or an open wire is found in the harness, repair the damaged section of the wiring or replace the harness.

4. 4

   Replace Actuator (If Applicable)

   If the wiring tests good but the actuator solenoid fails the resistance test (or is physically seized/damaged), remove the mounting hardware and linkage connecting the actuator to the turbocharger wastegate. Install the new wastegate actuator assembly and calibrate/adjust the rod length if required by the specific engine manual.

5. 5

   Reassemble

   Reconnect the actuator wiring harness and the battery.

6. 6

   Clear Codes

   Connect an electronic service tool (Case IH EST or Cummins INSITE) to the diagnostic port. Use the "Reset All Faults" command to clear the active and inactive 492 fault codes.

7. 7

   Test Run

   Start the engine and monitor the turbocharger boost pressure and wastegate duty cycle to ensure the fault does not return under load.