CARRIER 8P7719 - Caterpillar

Illustration 3 g01150773
Turn the ignition key switch to the ON position.
Refer to Illustration 3. Measure the voltage from the +Battery terminal of the data link connector to the −Battery terminal of the data link connector. Expected Result:The voltage is between 11.0 and 13.5 VDC for a 12 volt system or between 22.0 and 27.0 VDC for a 24 volt system.Results:
Yes - The battery supply voltage is correct at the data link connector. Proceed to Test Step 4.
No - The battery supply voltage is incorrect at the data link connector.Repair: Inspect the wiring and fuses to the connector. Repair the wiring or batteries and/or replace the wiring or batteries, as required. Send the vehicle to the OEM dealer for repair, if necessary.Verify that the repair eliminates the problem.STOPTest Step 4. Change the Components for Cat ET
Determine if another vehicle or another ECM is available with a Caterpillar electronic engine. Use the same cables in order to connect Cat ET to the other vehicle.
Try to establish communication between Cat ET and the engine ECM on the other vehicle.
If another engine is not available in the shop, find a different set of the electronic service tool cables. Ensure that the set of cables is a complete set.
Use the other cables or use different cables in order to connect the electronic service tool to the data link connector.
Turn the ignition key switch to the ON position.
If changing cables allows Cat ET to operate properly, perform the following procedure:
Turn the ignition key switch to the OFF/RESET position.
Replace the pieces from the old set of cables into the new set of cables that operates. Replace one piece at a time.
Try to establish communication after each of the pieces is replaced. Use this method to find the faulty piece.
If changing cables does not allow Cat ET to operate properly, connect another electronic service tool.
Turn the ignition key switch to the ON position. Expected Result:The original electronic service tool works on another vehicle.Results:
OK - The original electronic service tool works on another vehicle. Proceed to Test Step 5.
Not OK - A different electronic service tool works on the original vehicle. The electronic service tool is faulty.Repair: Replace the faulty electronic service tool.STOPTest Step 5. Check the Battery Voltage at the ECM
Illustration 4 g01150788
Pin locations on breakout T
(48) Unswitched +Battery
(52) Unswitched +Battery
(53) Unswitched +Battery
(55) Unswitched +Battery
(63) -Battery
(65) -Battery
(67) -Battery
(69) -Battery
(70) Ignition key switch
Turn the ignition key switch to the OFF/RESET position.
Verify that Cat ET is connected to the data link connector.
Disconnect vehicle harness connector P1 from ECM connector J1 and insert a breakout T.
Turn the ignition key switch to the ON position.
Measure the voltage between terminals P1-48 (unswitched +Battery) and P1-63 (−Battery).
Measure the voltage between terminals P1-52 (unswitched +Battery) and P1-65 (-Battery).
Measure the voltage between terminals P1-53 (unswitched +Battery) and P1- 67 (-Battery).
Measure the voltage between terminals P1-55 (unswitched +Battery) and P1-69 (-Battery).
Measure the voltage between terminals P1-70 (ignition key switch) and P1-65 (-Battery).
Measure the voltage between the vehicle harness connector P1 terminal 70 (ignition key switch) and terminal