GAUGE GP-PRESSURE 2686734 - Caterpillar

Illustration 1 g01226962
Cat Data Link connectionsThis failure results in codes that are logged against an ECM that can not be explained. The Power Train ECM cannot communicate with the Engine ECM or the ECM appears to work intermittently. Test Step 1. VERIFY THE HARDWARE AND THE SOFTWARE PART NUMBERS
Verify that the following information is correct:
The part number of the software of the Power Train ECM
The part number of the "Engine ECM flash software"
The part number of the Power Train ECM
The part number of the Engine ECM Note: Consult the Business Unit that produces the product for the correct part numbers of the configuration software. Expected Result:All part numbers are correct. Results:
OK - All part numbers are correct. Proceed to Test Step 2.
NOT OK - All part numbers are NOT correct. The part number of the Power Train ECM may be incorrect. The part number of the Engine ECM may be incorrect. The incorrect configuration software may also be installed. Repair: Replace the incorrect ECM with an ECM that has the correct part number. Flash the correct configuration software. See Troubleshooting, "Electronic Control Module - Flash Program".STOPTest Step 2. INSPECT THE HARNESS CONNECTIONS
Turn the disconnect switch to the OFF position.
Inspect all harness connections that are related to the Cat Data Link. Make sure that the connectors are clean and tight.
Check the connectors for proper mating.
Check the wires at the connector.
Check each wire for nicks or signs of abrasion in the insulation.
Check for moisture at the connector.
Check the connectors for dirty contacts or corroded contacts.
Check each pin and each socket of the machine harness connectors. Expected Result:The machine harness connectors are tight and free of corrosion. Results:
OK - The machine harness connectors are tight and free of corrosion. Proceed to Test Step 3.
NOT OK - The machine harness connectors are in need of repair.Repair: Repair the machine harness or replace the machine harness. STOPTest Step 3. CHECK FOR SHORTS TO GROUND
The disconnect switch remains in the OFF position.
Disconnect the machine harness from all electronic control modules that use the CATdata link.
At the machine harness for the Power Train ECM, measure the resistance between frame ground and connector contacts J1-10 (wire 893-GN) and J1-20 (wire 892-BR) of the Cat Data Link circuit. Expected Result:The resistance is greater than 5000 ohms. Results:
OK - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. Proceed to Test Step 4.
NOT OK - The resistance is less than 5000 ohms. The machine harness has failed. Repair: There is a short between frame ground and the Cat Data Link circuit in the machine harness. Repair the machine harness or replace the machine harness. STOPTest Step 4. CHECK FOR A SHORT TO THE +BATTERY CIRCUIT
The disconnect switch remains in the OFF position.
All related electronic control modules remain disconnected from the machine harness.
At the machine harness connector for the Power Train ECM, perform the checks that are listed here:
Measure the resistance between the connector contact J1-39 (wire 140-RD) and connector contact J1-10 (wire 893-GN).
Measure the