Caterpillar C9 Engine – DTC 15 164-3

Injection Actuation Pressure Voltage High

Fault Description

The Engine Control Module (ECM) detects that the voltage in the injection actuation pressure circuit exceeds 4.8 VDC for more than 0.6 seconds while cold mode is not active.

The injection actuation pressure sensor monitors the oil pressure in the high-pressure oil manifold. This high-pressure oil is crucial for injector actuation and fuel injection pressure regulation. The ECM relies on input from this sensor to calculate and control the fuel injection process by adjusting the injection actuation pressure control valve.

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Possible Causes

1. ECM Connection Issue – Loose or faulty ECM connection.
2. Faulty Injection Actuation Pressure Sensor – The sensor may be malfunctioning.
3. Wiring or Connection Fault – Damaged or loose wiring in the sensor circuit.

Troubleshooting & Corrective Actions

1. Inspect ECM Connection
   • Check for loose, damaged, or corroded connectors at the ECM.
   • Ensure all pins are properly seated and secure.
2. Test the Injection Actuation Pressure Sensor
   • Use a multimeter to measure the sensor output voltage.
   • Verify that the sensor provides a stable and correct voltage reading.
   • If the sensor is faulty, replace it.
3. Inspect Wiring & Connections
   • Visually check the wiring harness for signs of damage, wear, or loose connections.
   • Ensure there are no shorts, open circuits, or broken wires.
   • Repair or replace damaged wiring as necessary.

More repair case for Caterpillar machine,please refer to:Caterpillar Machine Repair