COLLAR (Outer) 7G0418 - 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 the default conditions for event codes.
Table 1
Diagnostic Codes Table
Description Conditions which Generate this Code System Response
E043(1) Low System Voltage The battery voltage to the ECM is less than normal. The code is logged.
168-0 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 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 System Voltage intermittent/erratic 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 must be disconnected. The engine will begin the start-up cycle 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 g01227331
Typical schematic for the electrical power supply
Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove electrical power from the ECM.
Illustration 2 g01227322
Location of the components for the electrical power supply (typical left side engine view)
(1) Air shutoff solenoid
(2) Customer connector
(3) J1/P1 ECM connector
(4) J2/P2 ECM connector
Thoroughly inspect connectors (2), (3), and (4). Also, thoroughly inspect the terminal connections at the air shutoff mechanisms. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Illustration 3 g01227424
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 4 g01227426
P2 ECM connector
(P2-13) Air shutoff
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the customer connector that are associated with the circuit.
Check the allen head screw for each ECM connector for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" for the correct torque value.
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 problem in the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify