C13, C15, and C18 Engines Troubleshooting – Variable Valve Actuator Response – Test

System Operation Description:

Troubleshooting Procedure

Use this procedure to diagnose mechanical problems or electrical problems with the intake valve actuation system. The following diagnostic codes indicate that there is a mechanical problem or an electrical problem with the system:


Illustration 1 g02725693
(1) Control valve

(2) Pressure sensor

(3) Check valve

(4) Actuators

Table 1
Diagnostic Codes for Mechanical Problems or Electrical Problems with the Intake Valve Actuation System
J1939 Code CDL Code Description Conditions Which Can Cause The Code
2949-7 1922-7 Intake Valve Actuation Oil Pressure not responding This code can only occur soon after the engine has started.

This code indicates that the difference in rail pressure is incorrect while the control valve is opened and closed. The following conditions can cause this code:

A control valve that contains debris or a control valve that is not operating correctly

Damaged O-ring seal or missing O-ring seal.

2950-7 1901-7 Intake Valve Actuator #1 not responding The intake valve actuator is not responding correctly to the commands from the ECM. This can be caused by the following conditions:

There is an oil leak in the system.

There is a problem with an actuator.

The valve lash is incorrect.

The adjustment of an actuator is incorrect.

2951-7 1902-7 Intake Valve Actuator #2 not responding
2952-7 1903-7 Intake Valve Actuator #3 not responding
2953-7 1904-7 Intake Valve Actuator #4 not responding
2954-7 1905-7 Intake Valve Actuator #5 not responding
2955-7 1906-7 Intake Valve Actuator #6 not responding
2948-7 E1101 (2) Engine Intake Valve Actuation System Oil Pressure : Not Responding Properly The Engine Intake Valve Actuation System Oil Pressure did not change when the Engine Intake Valve Actuation System Oil Pressure solenoid is toggled.
2948-17 E488 (2) Engine Intake Valve Actuation System Oil Pressure : Low – moderate severity (2) The Engine Intake Valve Actuation System Oil Pressure solenoid is commanded closed, but the oil pressure does not go up.
Follow the troubleshooting procedure in order to identify the root cause of the problem.

Note: Resolve any electrical problems with the system before you use this procedure.

Symptoms

The following symptoms may occur if there is a problem with the intake valve actuation system.

 

  • Intermittent check engine light
  • Intermittent reductions in engine power

You may need to apply a load to the engine in order to verify that the problem is resolved. The test must be performed at 75 percent of the engine’s rated fuel rate for at least 30 seconds.

Table 2
Troubleshooting Test Steps Values Results
1. Check the Engine Oil LevelA. Stop the engine. Allow the engine to cool approximately 20 minutes so the oil level can stabilize.

B. Check the engine oil level.

Oil level Result: The engine oil level is OK.Record the engine oil level. Verify that the dipstick is calibrated correctly. Refer to Operation and Maintenance Manual, “Engine Oil Level Gauge – Calibrate”.

Proceed to Test Step 2.

Result: The engine oil level is low.

Verify that the dipstick is calibrated correctly. Refer to Operation and Maintenance Manual, “Engine Oil Level Gauge – Calibrate”.

Add engine oil to the proper level. Record the amount of engine oil that was added. Verify that the repair resolved the problem.

If the problem has not been eliminated, proceed to Test Step 2.

Result: The engine oil level is high.

Verify that the dipstick is calibrated correctly. Refer to Operation and Maintenance Manual, “Engine Oil Level Gauge – Calibrate”.

Record the amount of engine oil that was drained. Verify that the repair resolved the problem.

If the problem has not been eliminated, proceed to Test Step 8.

Table 3
C18 Oil Pressure Table
Engine Speed Pressure (kpa) Pressure (psi)
800 233 34
1400 326 47
1800 420 61
2100 503 73


Illustration 2 g02725393
C18 oil pressure map

Table 4
Troubleshooting Test Steps Values Results
2. Check the Engine Oil PressureA. Turn the keyswitch OFF.

B. Establish communication between the Caterpillar Electronic Technician (ET) and the engine ECM. The communication adapter must be communicating on both data links in order to perform this procedure. Refer to Troubleshooting, “Electronic Service Tools” for more information, if necessary.

C. Install a mechanical gauge to the engine in order to read engine oil pressure. Refer to Testing and Adjusting, “Engine Oil Pressure – Test”.

D. Turn the keyswitch OFF.

Oil pressure ( Refer to Table 3) Result: The engine oil pressure is within specifications.Proceed to Test Step 3.

Result: The engine oil pressure is low.

Record the engine oil pressure.

Record the engine rpm.

If there are any active diagnostic codes that are related to low oil pressure, refer to the appropriate topic in Troubleshooting, “Oil Pressure Is Low”.

If the pressure is constant throughout the rpm range, there is a problem with the circuit for the engine oil pressure sensor. Check the wire for the pressure sensor supply (terminal A) for an open circuit.

If there are no diagnostic codes that are related to low oil pressure, refer to Testing and Adjusting, “Engine Oil Pressure – Test”.

Verify that the repair resolved the problem.

3. Determine the Logged CodeA Connect to Cat ET.

B. Turn the keyswitch ON.

C. Check for active or logged diagnostic codes:

Codes Result: A 1922-7 or 2949-7 code is active or logged.Proceed to Test Step 4.

Result: A E488 (2), E1101 (2), 2498-7, or 2948-17 code is active or logged.

Proceed to Test Step 5.

Result: A 2950-7 through 2955-7 or a 1901-7 through 1906-7 code is active or logged.

Proceed to Test Step 8.


Illustration 3 g01318034
Holes on the side of the control valve


Illustration 4 g01304628
Positions of the spool

When the valve is fully open, the spool blocks approximately 40 percent of the hole.

(12) Spool


Illustration 5 g01304707
Checking the position of the spool with a penlight

(12) Spool

(13) Penlight

(14) Valve body

Table 5
Troubleshooting Test Steps Values Results
4. Check the Control ValveA. Turn the keyswitch OFF.

B. Disconnect the harness connector from the control valve. Carefully remove the control valve from the engine.

C. Refer to Illustration 3. Carefully wipe the oil from the holes on the side of the control valve.

D. Look for debris in the holes. Be sure to look at all of the holes.
Note any debris that was found in the holes. If large amounts of debris are found, determine the source of the debris before you continue with this procedure.

E. Remove the debris if the debris can be easily removed. Otherwise, replace the contaminated control valve with a new control valve.

F. Look through a hole in order to determine the position of spool (12) . The spool should be fully closed. It may be necessary to use a penlight to determine the position of the spool.

G. Shine penlight (13) into valve body (14) as shown in Illustration 5. Press the end of the penlight up against the valve body in order to direct as much light as possible into the valve body. Light shining between valve body (14) and spool (12) indicates that the spool is not fully closed.

Oil level Result: The spool was not fully closed when the control valve was removed from the engine.Perform the following procedure:

1. Replace the control valve.

2. Clear all logged codes.

3. Proceed to Test Step 10.

Result: The spool was fully closed when the control valve was removed from the engine.

Proceed to Test Step 5.


Illustration 6 g01329207
Actuator on a C18 engine

(15) Leak points near the solenoids

(16) Purge orifices


Illustration 7 g01313403
Right side view of the rear of a typical C18 engine.

Check valve (3) may be located at the top of the oil supply tube or at the bottom of the oil supply tube.

(3) Check valve

(23) Bottom of the tube for the oil supply to the rail


Illustration 8 g01317964
Top view of the right rear of a typical C18 engine.

Two O-ring seals are installed at location (26) between quill tube (24) and jumper tube (25) . One O-ring seal is installed at face seal (27) between jumper tube (25) and the valve cover base.

Locations (26) and (27) apply to each of the actuators.

(3) Check valve

(24) Quill tube

(25) Jumper tube

(26) Joint between the quill tube and the jumper tube

(27) Face seal between the jumper tube and the valve cover base


Illustration 9 g01317986
Right side view of the front of a typical C18 engine.

An O-ring seal is installed at locations (20) and (21) .

(20) Joint between the sensor and the valve cover base

(21) Joint between the control valve and the valve cover base

(26) Joint between the quill tube and the jumper tube

(27) Face seal between the jumper tube and the valve cover base

Table 6
Troubleshooting Test Steps Values Results
5. Perform a Leak TestReview the following information before you perform the leak test.
It is normal for oil to flow from some locations during this test.
Leak Points Near the Solenoids – Clearances for moving hydraulic components may cause slight oil leakage from locations (15) .

Purge Orifice – purge orifice (16) allows air to purge from the actuator. The purge orifice is located on the bottom of some actuators. Oil should stream from each purge orifice during this test.

Oil should not flow from some locations. The following problems can cause oil to flow from these locations:
1. Missing O-ring seal or damaged O-ring seal
2. A component is loose.
3. A component has an internal failure.

The locations where oil should not flow on C18 engines are shown in Illustrations 7, and 8.

A. Turn the keyswitch OFF.

B. Disconnect the connectors for the speed timing sensors. This will prevent the engine from starting.

C. Disconnect the connector for the control valve. This will prevent the control valve from opening during the leak test.

D. Remove the valve covers.

E. Wipe all of the engine oil away from the following components:
1. Face seals for the intake valve actuators
2. Connection between the cylinder head and the valve cover base
3. Plugged ports on the intake valve actuators
4. Plugged ports on the valve cover base
5. The solenoids for the intake valve actuator

Do not crank the engine for more than 30 seconds.
It may be necessary to have a second person crank the engine while you check for leaks.

F. Crank the engine.

G. Check for oil leaks around all of the components under the valve cover.

H. Verify that all of the ports in the oil rail are plugged.

I. Verify that the oil flows through the bleed orifice on the intake valve actuator.

Leak test Result: No leaks were detected.Proceed to Test Step 6.

Result: No leaks were detected and no oil flowed through the purge orifice.

Check the intake valve actuator system for debris that could restrict the flow of oil.

Proceed to Test Step 10.

Result: A leak was detected.

Determine the source of the leak and repair the leak. Clear all logged diagnostic codes.

Install the valve covers. Connect all electrical connectors.

Start the engine if a 2949-7 code was the only code that was logged. Run the engine for at least 30 seconds until the engine coolant temperature is greater than 70 °C (158 °F). If a 2949-7 code does not return, the repair is complete.

Proceed to Test Step 10.

6. Check the Check ValveA. Remove the check valve. Refer to Illustration 1.

B. Inspect the check valve. Look for debris that could cause the check valve to stick.

Check valve Result: The check valve is “OK”.Proceed to Test Step 7.

Result: The check valve is damaged.

Replace the check valve. Proceed to Test Step 10.

A E488 (2), E1101 (2), 2498-7, 1922-7, 2949-7 or 2948-17 code is active or logged. proceed to Test Step 7.

Result: A 2950-7 through 2955-7 or a 1901-7 through 1906-7 code is active or logged.
Proceed to Test Step 8.


Illustration 10 g01329453
Typical example

(28) Sensor connector

(29) Intake valve actuation pressure sensor

(30) Fabricated tool

Table 7
Air Pressure Versus Signal Voltage
Air Pressure (psi) Range Low (VDC) Typical Voltage (VDC) Range High (VDC)
0 0.3 0.5 0.7
50 0.8 0.9 1.1
100 1.2 1.3 1.5
Table 8
Troubleshooting Test Steps Values Results
7. Test the Intake Valve Actuation Pressure Sensor

A. A pressure regulating assembly will be used to regulate air pressure to the intake valve actuation pressure sensor. Refer to Illustration 10. In addition to the pressure regulating assembly, the technician will need a digital multimeter and two 7X-1708 Multimeter Probes .
The fabricated tool consists of the following fittings and components:
1. 5/16 JIC Female to 1/4 JIC Male
2. 1/4 JIC Female Swivel to 1/4 NPT Male
3. 1/4 to 1/4 Male NPT
4. Pressure regulator

B. Fabricate the above assembly.

C. Turn the keyswitch OFF.

D. Disconnect the connector for the intake valve actuation pressure sensor.

E. Remove the intake valve actuation pressure sensor from the valve cover base.

F. Install the fittings and the pressure regulator onto the intake valve actuation pressure sensor.

G. Connect the connector for the intake valve actuation pressure sensor to the engine harness.

Ensure that the air pressure setting is less than 50 psi before applying air pressure onto the test apparatus.

H. Apply shop air pressure to the assembly.

I. Turn the keyswitch ON.

J. Measure the voltage between terminals 2 and 3 at the sensor connector.

K. Apply the air pressure that is indicated in Table 7 to the intake valve actuation pressure sensor. Record the voltage measurements at the different air pressures.

Pressure sensor Result: The voltage measurements are within range.

Proceed to Test Step 8.

Result: The voltage measurements are not within the acceptable range.

Replace the intake valve actuation pressure sensor.

Proceed to Test Step 10.

8. Perform the Automatic “Cylinder Cutout Test”

A. Start the engine.

B. Access the “Cylinder Cutout Test” in the “Diagnostic Tests” under the “Diagnostics” menu.

C. Select the “Automatic Cylinder Cutout Test” on Cat ET.

D. Start the test.

Cylinder Cutout Test Result: All of the cylinders indicated “OK” during the “Cylinder Cutout Test”.

Proceed to Test Step 9.

Result: One or more cylinders failed the “Cylinder Cutout Test”.

Diagnose the problem and then repair the cylinders that failed the “Cylinder Cutout Test” before continuing with this procedure. Clear all logged diagnostic codes. Verify that the repair has eliminated the problem in the cylinder.

Proceed to Test Step 10.

9. Set the Lash Settings for the Intake Valve Actuator

A. Turn the keyswitch OFF.

B. Allow the engine to cool.

C. Remove the valve cover(s) from the engine.

D. Check the lash settings for the intake valve actuators. Refer to Testing and Adjusting for the proper procedure.

Lash settings Result: The lash is set to specification.

Proceed to Test Step 10.

*10. Perform the “Intake Valve Actuator Test”
The “Intake Valve Actuator Test” is not valid until a “Cylinder Cutout Test” has shown all of the cylinders to be functioning properly.

A. Start the engine. Allow the engine to operate until the coolant temperature is at least
70 °C (158 °F).

B. Access the “Intake Valve Actuator Test” in the “Diagnostic Tests” under the “Diagnostic” menu.

C. After you adhere to the warnings, start the automatic “Intake Valve Actuator Test”.

The test will cycle two times. Once the test is complete the engine speed will increase to 2100 rpm for 15 seconds. An “OK” or “Not OK” will be displayed once the test is complete.

Intake Valve Actuator Test Result: All cylinders indicate “OK”.

Return the unit to service.

Result: One or more cylinders indicate “Not OK”.

Proceed to Test Step 11.

11. Replace the valve actuator unit

A. Replace the suspect intake valve actuator.

B. Perform the “Intake Valve Actuator Test”

Actuator unit Result: The test completed successfully.

Return the unit to service.

Result: The test did not complete successfully. There are additional codes.

Troubleshoot the additional codes. Refer to Troubleshooting for the correct procedure.

Test Step 1.

Complete the procedure in the order in which the steps are listed.

Results:

 

  • The procedure corrected the issue. – STOP 
  • The procedure did not correct the issue. –Repair: Contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).

    STOP

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