994D WHEEL LOADER ELECTRONIC SYSTEMS GUIDE Caterpillar

Electrical Component Locations

Usage:

Machine Component Location

Electronic Control Modules (ECM)

NOTE: When locating the following components, the right and left side of the machine is in reference to the operator sitting in the cab.

(1) VIMS interface module #2. (2) VIMS interface module #1. (3) VIMS main module. (4) Power train ECM.

The machine location for VIMS interface module #2, VIMS interface module #1, VIMS main module and the power train ECM is behind the outside of the cab.

(5) Engine ECM.

The machine location for the engine ECM is on the left side of the machine between the radiator and engine.

Sensors And Senders

Ambient Air Temperature Sensor

(1) Ambient air temperature sensor.

The machine location for the ambient air temperature sensor is behind the outside of the cab.

Coolant Temperature Sensor And Jacket Water Temperature Sender

(1) Coolant temperature sensor. (2) Jacket water temperature sender.

The machine location for the coolant temperature sensor and jacket water temperature sender is on the right side of the machine next to the radiator.

Hydraulic Oil Temperature Sender And Hydraulic Oil Temperature Sensor

(1) Hydraulic oil temperature sender. (2) Hydraulic oil temperature sensor.

The machine location for the hydraulic oil temperature sender and hydraulic oil temperature sensor is near the rear lower right hand side of the hydraulic tank.

Lift Cylinder Head End Pressure Sensor

(1) Lift cylinder head end pressure sensor.

The machine location for the lift cylinder head end pressure sensor is to the left side of the hydraulic valve on the front frame by articulation joint.

Tilt Cylinder Pressure Sensor

(1) Tilt cylinder pressure sensor.

The machine location for the tilt cylinder pressure sensor is to the right side of the hydraulic valve on the front frame by articulation joint.

Torque Converter Oil Temperature Sensor And Torque Converter Oil Temperature Sender

(1) Torque converter oil temperature sensor. (2) Torque converter oil temperature sender.

The machine location for the torque converter oil temperature sensor and torque converter oil temperature sender is on the front right side of the torque converter.

Transmission Output Speed Sensor

(1) Transmission output speed sensor.

The machine location for the transmission output speed sensor is on the back left side of the transmission above the output shaft.

Engine Oil Pressure Sensor #1

(1) Engine oil pressure sensor #1.

The machine location for the engine oil pressure sensor #1 is on the right side of the machine to the front of the oil filters.

Engine Oil Pressure Sensor #2

(1) Engine oil pressure sensor #2.

The machine location for the engine oil pressure sensor #2 is on the right side of the machine to the back of the oil filters.

Atmospheric Pressure Sensor

(1) Atmospheric pressure sensor.

The machine location for the atmospheric pressure sensor is between the engine ECM and radiator.

Crankcase Pressure Sensor

(1) Crankcase pressure sensor.

The machine location for the crankcase pressure sensor is on the left side of the machine in front of the power train filters.

Timing Speed Sender

(1) Timing speed sender.

The machine location for the timing speed sender is on the left side of the machine near the fly wheel housing.

Aftercooler Temperature Sensor

(1) Aftercooler temperature sensor.

The machine location for the aftercooler temperature sensor is on the left side of the machine, front of the engine next to the fire wall by the lifting hook.

Aftercooler Temperature Sender

(1) Aftercooler temperature sender.

The machine location for the aftercooler temperature sender is on the left side of the machine, front of the engine next to the fire wall by the lifting hook.

Left Hand Turbo Inlet Exhaust Temperature Sensor

(1) Left hand turbo inlet exhaust temperature sensor.

The machine location for the left hand turbo inlet exhaust temperature sensor is on the left side of the machine next to the left hand turbo.

Left Hand Turbo Inlet Pressure Sensor

(1) Left hand turbo inlet pressure sensor.

The machine location for the left hand turbo inlet pressure sensor is on the left side of the machine next to the left hand turbo.

Torque Converter Output Speed Sensor

(1) Torque converter output speed sensor.

The machine location for the torque converter output speed sensor is on the top of the torque converter output shaft.

Steering Oil Temperature Sender And Steering Oil Temperature Sensor

(1) Steering oil temperature sender. (2) Steering oil temperature sensor.

The machine location for the steering oil temperature sender and the steering oil temperature sensor is on the right side of the steering oil tank.

Autolube Pressure Sensor

(1) Autolube pressure sensor.

The machine location for the autolube pressure sensor is on the left side of the machine by the cab in the compartment for the autolube system.

Brake Oil Temperature Sender And Brake Oil Temperature Sensor

(1) Brake oil temperature sender. (2) Brake oil temperature sensor.

The machine location for the brake oil temperature sender and the brake oil temperature sensor is on the left side of the brake oil tank below the sight gauge.

Engine Fan Speed Sensor

(1) Engine fan speed sensor.

The machine location for the engine fan speed sensor is on the right side of the machine between the engine and the radiator.

System Air Pressure Sensor

(1) System air pressure sensor.

The machine location for the system air pressure sensor is on the right side the machine on the air tank.

Turbo Outlet Pressure Sensor

(1) Turbo outlet pressure sensor.

The machine location for the turbo outlet pressure sensor is on the middle back of the engine between the radiator and the fan drive.

Impeller Clutch Pressure Sensor

(1) Impeller clutch pressure sensor.

The machine location for the impeller clutch pressure sensor is on the torque converter control valve next to the torque converter output speed sensor.

Fuel Level Sender

(1) Fuel level sender.

The machine location for the fuel level sender is on the left side of the machine on the fuel tank.

Front Pump Drive Oil Temperature Sensor

(1) Front pump drive oil temperature sensor.

The machine location for the front pump drive oil temperature sensor is on the right side of the machine above the right steering cylinder on the rear of the front frame.

Lift Position Sensor

(1) Lift position sensor.

The machine location for the lift position sensor on the left side of the machine in front of the cab on the left lift arm.

Right Hand Turbo Inlet Exhaust Temperature Sensor

(1) Right hand turbo inlet exhaust temperature sensor.

The machine location for the right hand turbo inlet exhaust temperature sensor is on the right side of the machine above the third cylinder head.

Right Hand Turbo Inlet Pressure Sensor

(1) Right hand turbo inlet pressure sensor.

The machine location for the right hand turbo inlet exhaust temperature sensor is on the right side of the machine on the rear exhaust port.

Speed Timing Sensor

(1) Speed timing sensor.

The machine location for the speed timing sensor is on the right hand side of the machine by the firewall above the starter motors.

Switches

Neutralizer Pressure Switch And Brake Accumulator Pressure Switch

(1) Neutralizer pressure switch. (2) Brake accumulator pressure switch.

The machine location for the neutralizer pressure switch and the brake accumulator pressure switch are on left inside frame behind the cab on the brake valve.

Stop Lamp Switch And Park Brake Pressure Switch

(1) Stop lamp switch. (2) Park brake pressure switch.

The machine location for the stop lamp switch and the park brake pressure switch are on left inside frame behind the cab on the brake valve.

Engine Oil Level Switch

(1) Engine oil level switch.

The machine location for the engine oil level switch is on the right side of the machine, connected to the engine oil pan.

Steering Cooling Filter Pressure Switch And Hydraulic Cooling Filter Pressure Switch

(1) Steering cooling filter pressure switch. (2) Hydraulic cooling filter pressure switch.

The machine location for the steering cooling filter pressure switch and the hydraulic cooling filter pressure switch is on the right side of the machine behind the brake cooling oil tank.

Autolube Level Switch

(1) Autolube level switch.

The machine location for the autolube level switch is on the left side of the machine by the cab in the compartment for the autolube system. The autolube level switch is inside the tank.

Right Hydraulic Return To Tank Pressure Switch

(1) Right hydraulic return to tank pressure switch.

The machine location for the right hydraulic return to tank pressure switch is on the left side of the machine on the inner frame by the right front tire.

Left Hydraulic Return To Tank Pressure Switch

(1) Left hydraulic return to tank pressure switch.

The machine location for the left hydraulic return to tank pressure switch is on the left side of the machine on the inner frame by the left front tire.

Center Hydraulic Case Drain Pressure Switch

(1) Center hydraulic case drain pressure switch.

The machine location for the center hydraulic case drain pressure switch is above the hydraulic pumps in front of the cab.

Right Hydraulic Case Drain Pressure Switch

(1) Right hydraulic case drain pressure switch.

The machine location for the right hydraulic case drain pressure switch is on the upper structure of the machine in front of the cab to the right.

Left Hydraulic Case Drain Pressure Switch

(1) Left hydraulic case drain pressure switch.

The machine location for the left hydraulic case drain pressure switch is on the upper structure of the machine in front of the cab to the left.

AC HI LO Pressure Switch And AC Fan Override Pressure Switch

(1) AC HI LO pressure switch. (2) AC fan override pressure switch.

The machine location for the AC HI LO pressure switch and AC fan override pressure switch is on the right side of the machine on the AC motor.

Power Train Filter Pressure Switch

(1) Power train filter pressure switches.

The machine location for the power train filter pressure switches are on the left side of the machine behind the power train filters.

Right Steering Case Drain Pressure Switch

(1) Right steering case drain pressure switch.

The machine location for the right steering case drain pressure switch is on the right side of the machine located by the right rear tire.

Steering Return Filter Pressure Switch

(1) Steering return filter pressure switch.

The machine location for the steering return filter pressure switch is on the right side of the machine located by the right rear fire.

Left Steering Case Drain Pressure Switch

(1) Left steering case drain pressure switch.

The machine location for the left steering case drain pressure switch is on the left side of the machine located by the left rear tire.

Lift Kickout Switch

(1) Lift kickout switch.

The machine location for the lift kickout switch is on the right side of the machine in front of the cab on the right lift arm.

Bucket Positioner Switch

(1) Bucket positioner switch.

The machine location for the bucket positioner switch is on the upper structure, in front of the cab on the right tilt cylinder.

Steering Pressure Switch

(1) Steering pressure switch.

The machine location for the steering pressure switch is on the right side of the machine mounted behind the brake accumulator.

Left Hand Pump Steer Screen Switch And Right Hand Pump Steer Screen Switch

(1) Left hand pump steer screen switch. (2) Right hand pump steer screen switch.

The machine location for the left hand pump steer screen switch and the right hand pump steer screen switch are on left inside frame behind the cab below the brake valve.

Left Hand Hydraulic Pump Screen Pressure Switch, Center Hydraulic Pump Screen Pressure Switch And Right Hand Hydraulic Pump Screen Pressure Switch

(1) Left hand hydraulic pump screen pressure switch. (2) Center hydraulic pump screen pressure switch. (3) Right hand hydraulic pump screen pressure switch.

The machine location for the left hand hydraulic pump screen pressure switch, center hydraulic pump screen pressure switch and the right hand hydraulic pump screen pressure switch are located near the articulation joint under the pump drive.

Front Pump Drive Lube Pressure Switch

(1) Front pump drive lube pressure switch.

The machine location for the front pump drive lube pressure switch is on the right side of the machine above the right steering cylinder on the rear of the front frame.

Fuel Filter Pressure Switch

(1) Fuel filter pressure switch.

The machine location for the fuel filter pressure switch is on the right side of the machine next to the fuel filters by the AC motor.

Hydraulic Oil Level Switch

(1) Hydraulic oil level switch.

The machine location for the hydraulic oil level switch is on the left side of the machine in front of the cab on the lower left side of the hydraulic tank.

Hydraulic Pilot Filter Pressure Switch

(1) Hydraulic pilot filter pressure switch.

The machine location for the hydraulic pilot filter pressure switch is on the left side of the machine above the left steering cylinder by the articulation joint.