0302579 JOHNSON SCREW,Allen center

Table 1
Troubleshooting Test Steps Values Results
1. Check the Device that is Used for Circuit Protection
References will be made to system voltage. The system voltage of a typical 12V system is usually 12V to 16V.
The system voltage of a typical 24V system is usually 24V to 28V.
A. Measure the voltage on the supply side of the device that is used for circuit protection.
B. Measure the voltage on the load side of the device that is used for circuit protection.
12V to 16V on a 12V System
or
24V to 28V on a 24V System
Result: The voltage is equal to system voltage on both sides of the device that is used for circuit protection.
Proceed to Test Step 4.
Result: The voltage is not equal to system voltage on the supply side of the circuit protection device.
Repair: The problem is in the wiring to the battery. Repair the wiring. Proceed to Test Step 11.
Result: The voltage is not equal to system voltage on the load side of the circuit protection device.
Proceed to Test Step 2.
Illustration 1 g02958256
Table 2
Troubleshooting Test Steps Values Results
2. Reset the Protection Device
A. Reset the protection device or replace the circuit protection device.
B. Start the engine.
C. Perform the ARD nozzle heater circuit test in Cat ET.
Circuit Protection Device or Circuit
Result: The circuit protection trips.
Proceed to Test Step 3.
Result: The circuit protection does not trip.
There is a problem in the wiring circuit for the ARD heater. Proceed to Test Step 4.
3. Check the ARD Head
A. Turn the key to the OFF position
B. Disconnect the connector to the heater at the ARD head.
C. Reset the protection device or replace the circuit protection device.
D. Start the engine.
E. Perform the ARD nozzle heater circuit test in Cat ET.
ARD Head
Result: The circuit protection trips.
There is a problem in the wiring circuit for the ARD heater. Proceed to Test Step 4.
Result: The circuit protection does not trip.
Repair: Replace the ARD head and Proceed to Test Step 11.
4. Inspect the Wiring
A. Carefully inspect the wiring for the system. Look for the following problems:
Loose connectors or damaged connectors
Moisture on the connectors or the wiring
Damage that is caused by excessive heat
Damage that is caused by chafing
Improper routing of wiring
Damaged insulation
ARD Head retention clip
Wiring
Result: The wiring was not OK.
Repair: Replace the wiring or repair the wiring. Proceed to Test Step 11.
Result: The wiring was OK.
Proceed to Test Step 5.
Illustration 2 g03780878
CEM (typical)
(1) Relay for the ARD nozzle heater
Table 3
Troubleshooting Test Steps Values Results
5. Check for System Voltage past the ARD Heater Relay
A. Turn the keyswitch to the "ON" position.
B. Measure the voltage on terminal 2 on the ARD heater relay.
Equal to System Voltage
Result: The voltage on terminal 2 of the ARD heater relay is greater than zero volts.
Repair: The ARD heater relay is malfunctioning. Replace the ARD heater relay.
Proceed to Test Step 6.
Result: The voltage on terminal 2 is zero volts.
Proceed to Test Step 6.
6. Check for System Voltage at the ARD Heater Relay
A. Turn the keyswitch to the "ON" position.
B. Measure the voltage between terminal 3 and terminal 4 on the ARD heater relay.
Equal to System Voltage
Result: The voltage between terminal 3 and terminal 4 on the ARD heater relay is equal to system voltage.
Proceed to Test Step 7.
Result: The voltage between terminal 3 and terminal 4 on the ARD heater relay is not equal to system voltage.
Repair: The problem is between terminal 3 on the ARD heater relay and the circuit protection device or the problem is that terminal 4 does not have a good ground source. Repair the problem. Proceed to Test Step 12.
Illustration 3 g03780880
CEM (typical)
(2) Two-pin ARD heater wire connector
Table 4
Troubleshooting Test Steps Values Results
7. Check for System Voltage at the Two-Pin ARD Heater Wire Connector
A. Start the engine.
B. Establish communication between Cat ET and the ECM .
C. Perform the "ARD Nozzle Heater Circuit Test".
D. Measure the voltage between battery ground and terminal 1 on the two-pin ARD heater wire connector.
Equal to System Voltage
Result: The voltage between battery ground and terminal 1 is equal to system voltage.
Proceed to Test Step 11.
Result: The voltage between battery ground and terminal 1 is not system voltage.
Proceed to Test Step 8.
8. Check for Output Voltage from the ARD Heater Relay
A. Start the engine.
B. Establish communication between Cat ET and the ECM .
C. Perform the "ARD Nozzle Heater Circuit Test".
D. Measure the voltage between terminal 2 on the ARD heater relay and battery ground.
Power to the ECM must be OFF before reconnecting the relay.
Equal to System Voltage
Result: The voltage between terminal 2 and battery ground is equal to system voltage.
Repair: The problem is between terminal 2 on the ARD heater relay and the two pin ARD heater wire connector. Repair or replace the damaged wire. Proceed to Test Step 12.
Result: The voltage between terminal 2 and battery ground is not equal to system volta