POINT 5P2056 - Caterpillar

II. Three Second Power Up Test Is Ok.
PROBLEM 1 SYMPTOMS: EMS steering indicator LED and master fault light continue to FLASH after engine starts; warning horn ON when engine is running, but supplemental steering motor status light and motor are OFF. Possible Causes:A. Dump valve switch assembly adjusted too close to dump valve actuation pin or bad dump valve switch.B. Control module not receiving voltage from the alternator "R" terminal.C. Bad governor switch or circuit between switch and pin Y3 of the electronic control module is shorted to ground.D. Circuit from the electronic control module harness connector socket X2 to EMS panel is open.E. Circuit between dump valve switch assembly and pin Y6 of the electronic control module is shorted to ground.F. Bad electronic control module.G. Bad EMS panel. Troubleshooting:a) With dump valve actuation pin in the normal position, open the sure-seal connector for the electronic control module. Check resistance between pin Y6 and socket Y8. If less than 10,000 ohms, adjust switch. If resistance is still less than 10,000 ohms after adjusting the switch, then replace the switch.b) With the engine running and the 9 pin sure seal connector disconnected, check the voltage between sockets Y7 and Y8. If not at least 10 volts, check wiring between the receptacle and the alternator "R" terminal for shorts or opens. If OK, then repair or make a replacement of the alternator.c) With the engine stopped, disconnect switch OFF, and engine governor in the run position, measure resistance from pin Y3 to socket Y8 on the electronic control module harness connector. If less than 10,000 ohms, check switch adjustment. If resistance is still less than 10,000 ohms, check for shorts in wire between governor switch and receptacle pin Y3. If no shorts, replace the switch.d) With engine stopped and disconnect switch OFF, and sure-seal connector X disconnected, check continuity between socket X2 and the EMS receptacle socket 17. If no continuity, repair or make a replacement of the wire.e) With the electronic control module connector Y and the dump valve switch connector disconnected, check for continuity from pin Y6 to ground. If continuity, repair or make replacement of wire. f) If above items are OK, make replacement of the electronic control module.g) If the above items check OK, make a replacement of the EMS panel. PROBLEM 2 SYMPTOMS: EMS steering indicator LED and master fault light continue to FLASH after the engine starts; warning horn is ON when engine is running; supplemental steering motor status light is ON and motor runs when engine is running. Possible Causes:A. Bad steering pressure switch.B. Low primary steering hydraulic pressure.C. Circuit from the electronic control harness connector pin Y4 to socket Y8 is open.D. Circuit from the electronic control harness connector pin Y5 to socket Y8 is open. Troubleshooting:a) With engine stopped and disconnect switch OFF, disconnect the connector receptacle from steering pressure switch. Turn disconnect switch ON and start engine. Measure resistance across the pressure switch terminals A and B. If this