MANIFOLD GP-EXHAUST 9Y0784 - Caterpillar

Illustration 2 g01195063
P1 ECM connector (P1-5) PWM (−) (P1-66) PWM (+)
Illustration 3 g01195056
J37/P37 connector (Terminal 11) PWM (−) (Terminal 23) PWM (+)Test Step 1. Inspect Electrical Connectors and Wiring
Remove electrical power from the ECM.
Thoroughly inspect the ECM connector J1/P1. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for details.
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 allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
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, and the harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - The connectors and wiring are OK. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are not OK.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOPTest Step 2. Check the Supply Voltage to the Speed Control
Restore electrical power to the ECM.
Turn the ECS to the STOP position.
Measure the voltage between terminal 15 and terminal 16 on the speed control. Connect one probe of a voltmeter to the +Battery terminal of the speed control. Connect one probe of the voltmeter to the −Battery terminal of the speed control.Expected Result:The voltage is 24 3 VDC.Results:
OK - The voltage is 24 3 VDC. The voltage supply to the speed control is correct. Proceed to Test Step 4.
Not OK - The voltage is not 24 3 VDC. Proceed to Test Step 3.Test Step 3. Measure the Voltage to the Speed Control
Check the voltage between engine ground and the following test points. If voltage is not present at a test point, the problem is in the device, in the wire or in the connector that precedes the point in the circuit. Refer to Illustration 1 as a reference.
Table 1
Device     Terminal    
D1 diode     Either side    
"Dead Crank Switch"     Terminals for normal crank    
J30/P30 connector     9    
A7 resistor assembly     11    
A7 resistor assembly     12    
Generator Set Control (GSC)     RM2    
ECS     6    
ECS     10    
GSC     RM1    
GSC     RM39    
TB-4     17-22    
Turn the ECS to the OFF position.Expected Result:The voltage is 24 3 VDC at all test points.Results:
OK - The voltage is 24 3 VDC at all test points.Repair: Verify that the ground wire on terminal 16 has continuity to ground. If the ground wire on terminal 16 is OK, repair the wire between terminal 15 on the speed control and TB-4.STOP
Not OK - The voltage is not 24 3 VDC at a test point.Repair: Repair the device, connectors and/or wiring.STOPTest Step 4. Check the Throttle Position on Caterpillar Electronic Technician (ET)
Connect Cat ET to the service tool connector. Observe the position of