SOFTWARE GP-MONITOR 5523605 - Caterpillar

Use this procedure to troubleshoot the data link if a problem is suspected with the data link. Also, use this procedure if one of the diagnostic codes in Table 1 is active or easily repeated.
Table 1
Diagnostic Codes Table
CDL Code and Description Conditions which Generate this Code System Response
336-2 Engine Control Switch : Erratic, Intermittent, or Incorrect The Electronic Control Module (ECM) detects an intermittent signal for the engine control switch. The code is logged.
2348-9 SAE J1939 Data Link #2 : Abnormal Update Rate All communications on this data link have been lost. The code is logged. This procedure verifies the integrity of the Cat Data Link between the following components:
Service tool connector at the control box connector
Service tool connector at the display panelThis procedure verifies the integrity of the local CAN data link between the following components:
Engine Control Module (ECM)
Temperature Control Module (TCM)
Fuel control valve
Service tool connector at the control box connectorThis procedure verifies the integrity of the global CAN data link between the following components:
Engine Control Module (ECM)
Exhaust temperature module
Service tool connector at the display panelIf Caterpillar Electronic Technician (ET) will not communicate with the ECM, refer to Troubleshooting, "Electronic Service Tool Does Not Communicate" before you begin this procedure. The procedure verifies that electrical power is being supplied to the engine ECM and to the service tool connector.The data links provide a communication link between the various control modules on the application.Cat ET may display the following error message:"The version of the ECM is not recognized and the integrity of the changed parameters and displayed data is not guaranteed."If this message is displayed, the flash file in the ECM may be newer than the version of Cat ET, or the latest version of Cat ET has not been installed. Correct this condition prior to continuing with this procedure.
Illustration 1 g01816973
Schematic for the local CAN data link
Illustration 2 g03197377
Schematic for the Cat Data Link
Illustration 3 g03197358
Schematic for the global CAN data link
Illustration 4 g01444702
Terminal locations at the service tool connectors that are at the control box
(A) +Battery
(B) −Battery
(C) Local CAN shield
(D) Cat Data Link +
(E) Cat Data Link −
(F) Local CAN data link −
(G) Local CAN data link +
Illustration 5 g01559974
Terminal locations at the P1 ECM connector that are for the data links
(P1-8) Cat Data Link +
(P1-9) Cat Data Link −
(P1-34) Global CAN data link −
(P1-42) Global CAN shield
(P1-48) +Battery
(P1-50) Global CAN data link +
(P1-52) +Battery
(P1-53) +Battery
(P1-55) +Battery
(P1-57) +Battery
(P1-61) −Battery
(P1-63) −Battery
(P1-65) −Battery
(P1-67) −Battery
(P1-69) −Battery
(P1-70) Keyswitch
Illustration 6 g01326307
Terminal locations at the P2 ECM connector that are for the data link
(P2-11) Local CAN data link −
(P2-12) Local CAN data link +
(P2-23) Local CAN shield
Illustration 7 g03377718
Locations of the connectors that are associated with the data links. (Control box may not be located on engine.)
(1) Right rail connector
(2) J1/P1 ECM connectors
(3) J2/P2 ECM connectors
(4) Connector for the CAN shield jumper
(5) Service tool connector at the control box
(6) Termination resistor for the local CAN data link
(7) Termination resistor for the global CAN data link
(8) Control box connector for the front harness
(9) Engine interface connector
Illustration 8 g01355248
Terminal locations at the