SEAL ASSEM. 8J6860 - Caterpillar

System Operation Description:Use this procedure to troubleshoot the electrical system if a problem is suspected with the power to the engine's Electronic Control Module (ECM) or if any one of the diagnostic codes in Table 1 is active or easily repeated. Refer to Troubleshooting, "Event Code List" for information about event codes and the default trip points for these codes. You must access the monitoring system on Caterpillar Electronic Technician (ET) in order to view the current trip points for these codes.
Table 1
Diagnostic Codes Table
Code and Description Conditions which Generate this Code System Response
E043(1) Low System Voltage Warning The battery voltage to the ECM is less than normal. The code is logged.
168-0 Electrical System Voltage high The battery supply voltage is greater than 32 VDC for two seconds.
The engine's ECM has been powered for three seconds.
The engine is not being cranked.
168-1 Electrical System Voltage low The battery supply voltage is less than 9 VDC for two seconds.
The engine's ECM has been powered for three seconds.
The engine is not being cranked.
168-2 Electrical System Voltage erratic, intermittent, or incorrect The engine is running. The battery voltage falls below 9 VDC for at least .06 seconds. The voltage returns above 9 VDC.
or
Three voltage readings in the last seven seconds were below 9 VDC. To reduce resistance in the wiring harness, there are two isolated power connections to the ECM. The connections must be complete in order to ensure proper engine operation. There is a constant power supply to the ECM when the engine is shutdown. In order to shut off the power to the ECM, the main power needs to be disconnected. The engine will begin the start-up when the following conditions exist:
The ECM detects battery voltage at the keyswitch on P1-70.
The Start/Run/Stop Switch is activated.
Illustration 1 g01212645
Typical schematic
Illustration 2 g01212647
P1 ECM connector
(P1-5) Digital return
(P1-21) Start/Run/Stop input 1
(P1-22) Start/Run/Stop input 2
(P1-23) Emergency stop signal "C"
(P1-28) Emergency stop signal "D"
(P1-52) +Battery
(P1-53) +Battery
(P1-55) +Battery (ECM)
(P1-56) Air shutoff (NO)
(P1-63) −Battery
(P1-65) −Battery
(P1-70) Keyswitch
Illustration 3 g01234146
Location of ECM connectors
Illustration 4 g01212650
Customer connector
(Terminal 01) +Battery
(Terminal 02) +Battery
(Terminal 04) Air shutoff
(Terminal 09) Digital return
(Terminal 16) Emergency stop signal "D"
(Terminal 17) Emergency stop signal "C"
(Terminal 23) Start/Run/Stop input 1
(Terminal 24) Start/Run/Stop input 2
(Terminal 27) Keyswitch
(Terminal 34) −Battery
(Terminal 35) −Battery Test Step 1. Inspect Electrical Connectors and Wiring
Turn the main disconnect switch to the OFF position.
Thoroughly inspect the ECM connectors J1/P1. Inspect all of the other connectors. Refer to Troubleshooting, "Inspecting Electrical Connectors" for the proper procedure for inspecting system wiring.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Check the harness and the wiring for abrasion and for pinch points. Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a