3176C, 3406E and 3456 Industrial Engines Troubleshooting – Intake Manifold Air Pressure Is High

Use this procedure in order to troubleshoot high intake manifold pressure. Use this procedure if the following event code is active. Refer to Troubleshooting, “Event Codes” for information about event codes and the default trip points for these codes. You must access the monitoring system on Caterpillar Electronic Technician (ET) in order to view the current trip points for these codes.

Table 1
Diagnostic Codes Table
Code and Description Conditions which Generate this Code System Response
273-0 Turbocharger Outlet Pressure Sensor : High The Electronic Control Module (ECM) detects pressure that is above
200 kPa (29 psi).
The code is logged.
The value of the parameter is set to a pressure of
0 kPa (0 psi).

Probable Causes


  • Diagnostic codes 
  • Air inlet and exhaust restrictions 
  • Wastegate (if equipped) 
  • Full Load Setting (FLS) 

Recommended Actions

Diagnostic Codes

Use Cat ET to check for diagnostic codes that are active or logged. Troubleshoot any active codes before continuing with this procedure.

Air Inlet and Exhaust Restrictions


  1. Check the air filter for damage. If necessary, replace damaged air filters. Refer to the Operation and Maintenance Manual.


  1. Check the air inlet and exhaust system for restrictions and/or leaks. Refer to Systems Operation/Testing and Adjusting.

Wastegate (If Equipped)

Check for correct operation of the wastegate (if equipped). Refer to Systems Operation/Testing and Adjusting. If the wastegate actuator (if equipped) is faulty, replace the wastegate actuator (if equipped). Refer to Disassembly and Assembly.


Verify that the FLS is correct.

Intake Manifold Pressure Sensor

If an electrical problem with the intake manifold pressure sensor is suspected, refer to Troubleshooting, “Sensor Signal (Analog, Active) – Test” for information that is related to troubleshooting an electrical problem with the coolant level sensor.

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