In internal combustion engines that use hydraulic-fluid actuated fuel injectors, enhanced engine compression braking can be realized with simplified hydraulic control systems, by using fuel injector hydraulic fluid to open exhaust valves at or near the top of a compression stroke. The Raman pump signal is controlled with a gain GainRA evaluated based on the estimated gain Gainmeas so that all channels have a similar gain. A supporting element is disposed in a lower portion of the housing. If catastrophe damage occurs, the principal amount of the CHP mortgage may be reduced by the lesser of the value of the damage or the principal balance. The sides of the parallelogram have a length of at least 3.