318C Excavator Tool Control System Caterpillar

Engine and pump controller (1) is connected to the machine through two connectors. Each connector has 54 pins. The engine and pump controller receives input signals from various components on the machine. The engine and pump controller continuously monitors the input signals in order to control the output flow rate of the main pumps, engine speed and various components of the machine hydraulic systems.

Illustration 1	g00673776
Electronic controller (1) Engine and Pump Controller

Illustration 2	g00788560
Controller and connectors for the engine and pump controller

Note: The numbered pins in the above illustration are provided as reference points. The other pins are located by counting from the pins that are illustrated.

Table 1

Engine and Hydraulic Pump Control (Connector 171) (1)
Pin Number	Function	Type
1	Straight Travel Solenoid	Solenoid Output
2	Solenoid for Travel Speed Change	Solenoid Output
4	The Swing Brake Solenoid	Solenoid Output
5	Air Heater Relay
6	Free Swing Switch	Switch Input
7	Solenoid for Power Shift Reducing Valve.	Solenoid Output
8	Solenoid for Flow Limiter Valve	Solenoid Output
9	Primary NFC Pressure
13	Travel Alarm	Output
14	Mode Indicator for the AEC	Output
15	Travel Mode Indicator	Output
16	Speed Sensor "-"	Sensor Return
17	Starter Relay	Relay Output
19	Solenoid Return	Ground
20	Solenoid Return	Ground
23	Action Alarm	Output
24	Travel Alarm Indicator	Output
25	Engine Speed "+"	Sensor Input
26	Quick Coupler Switch	Switch Input
29	Coolant Temperature Sensor	Sensor Input
30	Fuel Level Sensor	Sensor Input (PWM)
31	Sensor Return
35	Alternator Terminal "R"	Sensor Input (Voltage)
36	Governor Actuator Position Feedback	Sensor Input (PWM)
37	Delivery Pressure Sensor For The First Pump	Sensor Input (PWM)
39	Hydraulic Oil Temperature Sensor	Sensor Input (PWM)
40	Sensor Return
44	Governor Actuator Position Command
45	Delivery Pressure Sensor for the Second Pump	Sensor Input (PWM)
47	Backup Switch	Switch Input

( 1 )

The connector contacts that are not listed are not used. The connector has 54 contacts.

Table 2

Engine and Hydraulic Pump Control (Connector 172) (1)
Pin Number	Function	Type
1	Unswitched + Battery pin	Power
2	Ground	Ground
4	Air Heater Relay	Solenoid Output
5	Auto Lube Failure
9	Engine Speed Dial 1	Switch Input
10	Engine Speed Dial 2	Switch Input
11	One touch Low Idle Switch	Switch Input
12	Mode Switch For The AEC	Switch Input
13	+Battery	Power
14	Ground	Ground
16	Overload Alarm Cancel Switch	Switch Input
17	Implement Pressure Switch	Switch Input
18	Status For Stem 2
19	Engine Speed Dial 3	Operational Switch Input
20	Engine Speed Dial 4	Operational Switch Input
21	Switch For Travel Mode	Switch Input
22	Travel Alarm Cancel Switch	Switch Input
23	Key Start Switch	Switch Input
28	Status For Activation 1	Output
29	Pressure Switch For The Control Lever	Switch Input
30	Left Travel Pressure Switch	Switch Input
31	Coolant Level Switch	Switch Input
32	Hydraulic Oil Level Switch	Switch Input
33	Data Link "+"	Input/Output
38	Clogged Fuel Filter
39	Pressure Switch for Travel Right	Switch Input
40	Engine Oil Level Switch	Switch Input
41	Engine Oil Pressure Switch	Switch Input
42	Switch for Clogged Filter	Switch Input
43	Data Link "-"	Input/Output
45	Status For Activation 3	Output
46	Status For Attachment Stem 4
47	Water Separator Level Switch	Switch Input
48	Switch for Clogged Air Cleaner	Switch Input
51	Clogged Primary Fuel Filter
52	Clogged Special Filter
53	Straight Travel Pressure Switch	Switch Input

( 1 )

The connector contacts that are not listed are not used. The connector has 54 contacts.