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AD: Dual Generator Upper Fault Detected

Test AD: Dual Generator Upper Fault Detected (p1105)

AD1 - Check Upper Generator Connections


AD1:






Check the upper generator connectors for damage and correct connection.






Are the upper generator connectors OK and correctly connected?

YES GO to AD2.

NO REPAIR the connections as necessary. CLEAR the PCM codes and TEST the system for normal operation.

AD2 - Check The Upper Generator Voltage B+ Voltage

AD2:






Measure the voltage at the B+ terminal of the upper generator.

Is the voltage equal to battery voltage?

YES GO to AD3.

NO CHECK B+ Circuit 38 (BK/O) including fuse links. REPAIR as necessary. CLEAR the PCM codes and TEST the system for normal operation.

AD3 - Check The Upper Generator A Circuit

AD3:






Measure the voltage between the upper generator C1020 terminal A, circuit 35 (OG/LB), harness side and ground.

Is the voltage greater than 10 volts?

YES GO to AD4.

NO CHECK upper generator A circuit 35 (OG~LB) including fuse links. REPAIR as necessary. CLEAR the codes and TEST the system for normal operation.

AD4 - Check Upper Generator I Circuit Voltage

AD4:






Measure the voltage between the upper generator C1020 terminal I, circuit 1185 (YE), harness side and ground.

Is the voltage greater than 10 volts?

YES GO to AD6.

NO GO to AD5.

AD5 - Check The Upper Generator I Circuit For High Resistance Or An Open

AD5:






Measure the resistance between the upper generator C1020 terminal I, circuit 35 (OG/LB), harness side and the PCM C154 pin 35, circuit 1183 (WH/YE) harness side.

Is the resistance less than 5 ohms?

YES GO to AD8.

NO REPAIR the circuit. TEST the system for normal operation.

AD6 - Check The Upper Generator Voltage

NOTE: After starting engine, wait at least two minutes for glow plugs to turn off.

AD6:






Measure the voltage between the battery terminals.

Is the voltage greater than 13 volts?

YES GO to AD7.

NO INSTALL a new upper generator. CLEAR the codes and TEST the system for normal operation.

AD7 - Check The Upper Generator Output

Verify the upper generator output. Refer to component test, Generator On-Vehicle Tests, Load Test.

Is the upper generator operating correctly?

YES The system is operating normally. RECONNECT all the connectors, CLEAR the codes and TEST the system for normal operation.

NO INSTALL a new upper generator. CLEAR the codes and TEST the system for normal operation.

AD8 - Check For Correct Module Operation

Check:

- for corrosion
- for pushed-out pins
- connector seated correctly

Connect any disconnected connectors.

Make sure all other system connectors are fully seated.

Operate the system and verify the concern is still present.

Is the concern still present?

YES INSTALL a new PCM. CLEAR the DTCs. REPEAT the PCM self-test.

NO The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.