CYLINDER GP-HYDRAULIC 1244622 - Caterpillar

Illustration 2 g03846524
Device 1 present
(1) Column 1
Illustration 3 g03846007
Device 1 and Device 2 present
(1) Column 1
(2) Multiple Device 1 and Device 2 can be displayed
(3) Device 2 is the affected ECM/device that cannot be recognized by Device 1. Device 2 is the ECM/device with the problem.
Table 4
Troubleshooting Test Steps Values Results
6. Use the System Communication Status to Determine the Cause
A. Determine if both ECM 1 and ECM 2 are present in the "ECM" column (1) within the "System Communication Status" screen. Refer to Illustration 3.
Component Identified
Result: ECM 1 and ECM 2 are both present.
Record the devices identified as ECM 1 and ECM 2 in column 1. Refer to Illustration 3.
Proceed to Test Step 7.
Result: Only ECM 1 is present.
Record the device identified as ECM 1 in column 1. Refer to Illustration 2.
Proceed to Test Step 9.
7. Check the Resistance of the Data link
A. Turn the breaker to the OFF position.
B. Measure the resistance of the data link between the following ECM 2 wiring harness connector terminals:
- +Data link and -Data link
60+/-10 Ohms
Result: The resistance is less than 50 Ohms.
Repair: There are more than 2 terminating resistors installed in the wiring harness or a short circuit has been detected. Repair or replace damaged components.
Proceed to Test Step 10.
Result: The resistance is 120 10 Ohms.
Repair: There is a problem with a terminating resistor. Check the resistance on each terminating resistor. Replace the failed terminating resistor.
Proceed to Test Step 10.
Result: The resistance is greater than 130 Ohms.
Repair: There is a problem with both terminating resistors or an open circuit has been detected.
Determine the cause of the problem. Repair or replace damaged components.
Proceed to Test Step 10.
Result: The resistance is 60 10 Ohms. The terminating resistors are OK.
Proceed to Test Step 8.
8. Check the Power and Ground to ECM 2
A. Turn the breaker to the ON position.
B. Measure the voltage between the following ECM 2 wiring harness connector terminals:
- +Battery and -Battery
Battery Voltage Result: The voltage is not equal to battery voltage.
Repair: There is an open or short in the wiring circuit. Repair or replace the wiring circuit. Refer to the machine-specific schematic for wiring information.
Proceed to Test Step 10.
Result: The voltage is equal to battery voltage.
Repair: Replace the component identified as ECM 2. Refer to Special Instruction, REHS8151 for special handling instructions if replacing a NOx sensor.
Proceed to Test Step 10.
9. Check the Resistance of the Data Link
A. Turn the breaker to the OFF position.
B. Measure the resistance of the data link between the following ECM 1 wiring harness connector terminals:
- +Data link and -Data link
60+/-10 Ohms
Result: The resistance is less than 50 Ohms.
Repair: There are more than two terminating resistors installed in the wiring harness or a short circuit has been detected. Repair or replace damaged components.
Proceed to Test Step 10.
Result: The resistance is 60 10 Ohms. The terminating resistors are OK.
Repair: Check the power, ground, and keyswitch (if applicable) supply to each module on the affected data link. Refer to the appropriate wiring diagram. Repair the power or ground supply to