MBE 4000 DDEC VI Troubleshooting – Section 9.13 Faulty Constant Throttle Valve Solenoid

Section 9.13
Faulty Constant Throttle Valve Solenoid

To determine if a faulty constant throttle valve CTV solenoid is causing excessive black or gray smoke, measure the resistance between wire 52 in the 55-pin connector and vehicle ground.‪

1. If the resistance is greater than 30 kΩ, replace the constant throttle valve; refer to MBE 4000 Service Manual (6SE420), Chapter 1, “Engine, — Engine Brake, CTV solenoid”. Verify the replacement of the CTV solenoid; refer to "9.13.1 Test Engine for Replaced CTV Solenoid" .
2. If the resistance is less than 30 kΩ, refer to "9.14 Improper Valve Clearance, Worn or Damaged Camshaft Lobes and Rollers" .

Section 9.13.1
Test Engine for Replaced CTV Solenoid

Perform the following steps to determine if the replaced CTV solenoid resolved the excessive exhaust smoke condition:‪

PERSONAL INJURY ‪
To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

1. Start and run the engine.
2. Run the engine at idle under no-load conditions for approximately five minutes, allowing the engine coolant to reach normal operating range, approximately 88-96°C (190-205°F).
3. Visually inspect exhaust for excessive smoke.
   1. If the engine smoke emission appears normal, no further troubleshooting is required. Shut down the engine.
   2. If the engine exhaust smoke is excessively black or gray, shut down the engine. Refer to "9.14 Improper Valve Clearance, Worn or Damaged Camshaft Lobes and Rollers" .