ROD 1793036 - Caterpillar

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 g03735953
(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 error 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. Note: Resolve any electrical problems with the system before you use this procedure.SymptomsThe following symptoms may occur if there is a problem with the intake valve actuation system.
Intermittent check engine light
Intermittent reductions in engine powerYou 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 rated fuel rate for at least 30 seconds.
Table 2
Troubleshooting Test Steps Values Results
1. Check the Engine Oil Level
A. 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.
Repair : 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.
Repair : 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