GEAR-DRIVER 1569644 - Caterpillar

Illustration 1 g01182547
Retarder circuitThe components of the retarder circuit are the Power Train/Chassis Electronic Control Module (Power Train/Chassis ECM), the retarder lever switch, the automatic retarder switch, the front service brake and retarder oil pressure switch, the rear service brake and retarder oil pressure switch, the retarder supply solenoid valve for the front brakes, the retarder supply solenoid valve for the rear brakes, the retarder control solenoid valve for the front brakes, the retarder control solenoid valve for the rear brakes and the engine speed sensor.
Illustration 2 g01182548
Front view of cab (front cover plate removed) (1) Power Train/Chassis ECM
Illustration 3 g01182550
Cab (2) Retarder lever switchWith the battery disconnect switch in the ON position, 24 V power is supplied from the batteries via circuit breaker #1 to Power Train/Chassis ECM (1) .With the key start switch in the ON position, 24 V power is supplied from the batteries via circuit breaker #13, to retarder lever switch (2) and Power Train/Chassis ECM (1).
Illustration 4 g01035340
Rear view of engine (3) Engine speed sensor
Illustration 5 g03795545
Top view of retarder control valve (4) Rear service brake and retarder oil pressure switch (5) Front service brake and retarder oil pressure switch
Illustration 6 g01183709
View of retarder control valve (6) Retarder supply solenoid valve for the front brakes (7) Retarder supply solenoid valve for the rear brakes (8) Retarder control solenoid valve for the front brakes (9) Retarder control solenoid valve for the rear brakesPower Train/Chassis ECM (1) has inputs that determine the output to retarder supply solenoids (6) and (7) and to retarder control solenoids (8) and (9). Retarder lever switch (2) is an input to Power Train/Chassis ECM (1). Retarder lever switch (2) sends a Pulse Width Modulated (PWM) signal to Power Train/Chassis ECM (1). Power Train/Chassis ECM (1) controls the retarder solenoids proportionally to retarder lever position (2) .Rear service brake and retarder oil pressure switch (4) and front service brake and retarder oil pressure switch (5) close contacts when the retarder is active. This signal is then sent to Power Train/Chassis ECM (1). This signal causes the retarder to be Canceled when the service brake is applied.
Illustration 7 g01182552
Dash panel (10) Automatic retarder switchEngine speed sensor (3) is an input to Power Train/Chassis ECM (1). The engine speed sensor sends an inductive pulse signal for engine rpm to Power Train/Chassis ECM (1). Power Train/Chassis ECM (1) uses the engine speed signal to calculate at what point the retarder must operate.When automatic retarder switch (10) is in the ON position, the automatic retarding system will operate. When the engine speed has reached 2160 rpm, Power Train/Chassis ECM (1) will pulse the retarder solenoids.This retarding pulse is used to bring the oil pressure within the braking system up to operating pressure. If the engine speed increases from 2160 rpm to