3126B and 3126E On-highway Engines Caterpillar

Use this procedure under the following situation:

Use the following information in order to troubleshoot the system when there is an active code:

• 164-02 Injection Actuation Pr Sensor Erratic (15)

Note: This procedure can check the accuracy of the injection actuation pressure sensor against a pressure gauge.

The following background information is related to the following procedure:

The injection actuation pressure sensor measures the pressure of the oil in the high-pressure oil manifold. The high-pressure oil in the manifold is used to actuate the injectors and the high-pressure oil is used to control the fuel injection pressure. Fuel injection pressure is based on inputs from the sensors. The inputs are used by the ECM for calculating the fuel injection pressure. The ECM uses the reading from the injection actuation pressure sensor in order to control the operation of the injection actuation pressure control valve.

Illustration 1	g00725343
location of the injection actuation pressure control valve

Illustration 2	g00725355
Schematic for the injection actuation pressure sensor

Illustration 3	g00725426
Locations for the ECM terminals

Test Step 1. Use an Electronic Service Tool to Check for Active Diagnostic Codes.

1. Connect the electronic service tool to the cab data link connector.

2. Turn the ignition key switch to the ON position.

   Note: If the 164-02 Injection Actuation Pr Sensor Erratic (15) is not active or logged, try to start the engine.

   Note: If 164-03 Injection Actuation Pr Sensor Open Circuit (15) or 164-04 Injection Actuation Pr Sensor Short Circuit (15) is active, refer to Troubleshooting, "Engine Pressure Sensor Open or Short Circuit-Test".

Expected Result:

164-02 Injection Actuation Pressure Erratic is active.

Results:

• Yes - The engine will start. Proceed to Test Step 3.

• No - The engine will not start. Proceed to Test Step 2.

Test Step 2. Disconnect the Injection Actuation Pressure Sensor and Start the Engine.

1. Turn the ignition key switch to the OFF position.

2. Disconnect the electrical connector J204/P204 for the injection actuation pressure sensor from the engine harness.

3. Try to start the engine.

Expected Result:

The engine starts.

Results:

• Yes - Proceed to Test Step 3.

• No -

  Repair: Reconnect the electrical connector J204/P204 for the injection actuation pressure sensor to the engine harness. Refer to Troubleshooting, "Engine Cranks but Will Not Start".

  STOP

Test Step 3. Inspect Electrical Connectors and Wiring.

1. Thoroughly inspect the connector J204/P204 for the injection actuation pressure sensor and inspect the ECM engine harness connector J2/P2. Refer to Troubleshooting, "Electrical Connectors-Inspect" for details.

2. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the injection actuation pressure sensor (terminals 61 and terminal 62).

3. Check the ECM connector (allen head screw) for the proper torque of 6.0 N·m (55 lb in).

4. Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM.

Expected Result:

All connectors, pins, and sockets should be completely coupled and/or inserted and the harness and wiring should be free of corrosion, abrasion, or pinch points.

Results:

• OK - Proceed to Test Step 4.

• Not OK -

  Repair: Perform the following repair:Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.

  STOP

Test Step 4. Check the Sensor Status with the Engine Off.

1. Connect the electronic service tool to the cab data link connector.

2. Turn the ignition key switch to the ON position.

3. Check the injection actuation pressure on the electronic service tool status screen.

   Note: The following codes will cause the injection actuation pressure sensor to default to 17500 kPa (2538 psi).

   • 164-03 Injection Actuation Pr Open Circuit (15)

   • 164-04 Injection Actuation Pr Sensor Short Circuit (15)

   • 232-03 5 Volt Supply Above Normal (21)

   • 232-04 5 Volt Supply Below Normal (21)

Expected Result:

The injection actuation pressure sensor indicates 0 kPa (0 psi).

Results:

• Yes - Proceed to Test Step 6.

• No - Proceed to Test Step 5.

Test Step 5. Check the Voltage Supply of the Injection Actuation Pressure Sensor.

1. Turn the ignition key switch to the OFF position.

2. Disconnect the electrical connector J204/P204 for the injection actuation pressure sensor from the engine harness.

3. Connect a 3-Terminal breakout T to the electrical connector J204 only.

4. Turn the ignition key switch to the ON position.

5. Use a digital multimeter that is set on DC voltage. Measure the voltage supply from terminal A to Terminal B at the breakout T.

Expected Result:

The voltage reading should be between 4.5 to 5.5 VDC.

Results:

• Yes - Proceed to Test Step 6.

• No -

  Repair: The voltage supply for the injection actuation pressure sensor is not correct. Refer to Troubleshooting, "5 V Engine Pressure Sensor Supply Circuit - Test".

  STOP

Test Step 6. Compare the Injection Actuation Pressure Sensor Reading to a Pressure Gauge Reading.

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Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak.

1. Turn the ignition key switch to the OFF position.

2. Install a 8T-0852 Pressure Gauge to an oil supply port on the high-pressure oil rail that is located on the cylinder head.

3. Connect the electronic service tool to the cab data link connector.

4. Start the engine.

5. Go to the "Injection Actuation Pressure Test" on the Diagnostic Menu of the electronic service tool.

6. Start the test and monitor the Injection Actuation Pressure Sensor reading from the electronic service tool. Compare the pressure reading from the electronic service tool to the pressure reading on the 8T-0852 Pressure Gauge . Perform a comparison of the two different pressure indicators at varying engine rpm.

   Note: Use Table 1 for the approximate range for the injection actuation pressure sensor. Compare the 8T-0852 Pressure Gauge pressure reading to the pressure reading from the table.

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   Table 1

   Service Tool Pressure Reading	Pressure Gauge Reading Range
   6000 kPa	4000-7800 kPa (580-1130 psi)
   10000 kPa	8000-11800 kPa (1160-1710 psi)
   15000 kPa	13000-16800 kPa (1885-2435 psi)
   23000 kPa	21000-24800 kPa (3045-3595 psi)

Expected Result:

The reading that is displayed on the electronic service tool and the reading on the pressure gauge readings agree.

Results:

• Yes -

  Repair: The injection actuation pressure sensor and the ECM are working properly. Refer to Troubleshooting, "Troubleshooting without a Diagnostic Code".

  STOP

• No -

  Repair: Temporarily replace the injection actuation pressure sensor and repeat the test. Replace the injection actuation pressure sensor if this corrects the problem. If the new sensor is out of the range, then the pressure gauge is faulty.

  STOP