Engine Brake Operation

p3 dm 13.03.002

Notice: Do not allow the engine to exceed its governed speed, or serious engine damage could result.

Note:  Depending on the brake type, the engine brake may be disabled when engine temperature falls below a set level.

The engine brake control depends on vehicle configuration. On some vehicles, there is an engine brake (ENG BRK) switch located in the right-hand pod on the steering wheel that is used to turn the engine brake on and off, and an engine brake level switch on the dash used to set the intensity—high, medium, or low. See Fig. and Fig..

On vehicles equipped with a column-mounted Detroit multifunction control, the engine brake is controlled by the lever position, see Fig.. At the top position, the engine brake is off, and at the three lower positions, the engine brake is on and the intensity (low, medium, high) increases with each step down.

Note: On vehicles equipped with a Detroit multifunction control, setting the engine brake with the cruise control set activates Deceleration Mode. Setting the cruise control while the engine brake is on activates Descent Control Mode. For information on these modes, see "Cruise Control" in Ignition Switch and Key.

On vehicles equipped with an engine brake switch in the right-hand pod on the steering wheel, operate the engine brake after the engine is warmed up and the vehicle is in motion, as follows:

  1. Remove feet from both the clutch and accelerator pedals.
  2. Press the upper half of the on/off switch (see Fig.) to turn the engine brake on. The engine brake will engage at the rate last set on the engine brake intensity switch and the engine brake lamp will illuminate.
  3. Press the upper or lower half of the intensity switch (see Fig.) to select the desired braking intensity.
    Use the intensity switch set at the LOW position when driving on flat, open stretches of road. If the service brakes are still required to slow down on a grade, switch to a higher setting on the dash switch to maintain constant speed of descent. Grade descent speed should be such that the service brakes are used infrequently and remain cool, thus retaining their effectiveness.
  4. For maximum retarding, maintain the top governed speed of the engine through the appropriate selection of gears. When shifting gears, the engine brake will disengage when the clutch pedal is depressed, then engage when the clutch pedal is released.
  5. To cancel the engine brake application, press the lower half of the on/off switch.

    Fig. 1, Steering Wheel Switches

    Fig. 2, Engine Brake Level Switch

    1. Off

    2. Low

    3. Medium

    4. High

    Fig. 3, Engine Brake Positions, Detroit Multifunction Control

Note:
Parent topic: Engine Brake
Document Number: 0000113540
Manual Publication Date: 2025-02-11
Topic Publication Date: 2024-05-06