DTC P1105: Upper Generator Fault Detected
WARNING: This page is about a different car, the 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, and 2004 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
- Check Upper Generator Connections
Turn ignition switch to LOCK position. Disconnect upper generator connectors. Inspect connectors for damage or loose connections. Are the upper generator connectors okay and correctly connected? If yes, restore connections and go to next step. If no, repair as necessary. - Check Upper Generator B+ Voltage
Measure voltage between ground and upper generator terminal B+ (Red wire). Is the voltage equal to battery voltage? If yes, go to next step. If no, repair circuit or fusible links between batteries and upper generator. See WIRING DIAGRAMS . Clear DTCs. Test system for normal operation. - Check Upper Generator "A" Circuit
Disconnect upper generator 3-pin connector. Measure voltage between ground and upper generator connector terminal No. 3 (Orange/Light Blue wire). See Fig 1. Is the voltage equal to battery voltage? If yes, go to next step. If no, repair open in circuit or fusible links between batteries and upper generator. See WIRING DIAGRAMS . Clear DTCs. Test system for normal operation. - Check Upper Generator "I" Circuit Voltage
Turn ignition switch to RUN position. Measure voltage between ground and upper generator connector terminal No. 1 (Light Green/Red wire). See Fig 1. Is the voltage greater than 10 volts? If yes, go to step 6. If no, go to next step. - Check Upper Generator "I" Circuit For An Open Or Short To Ground
Turn ignition switch to LOCK position. Disconnect PCM connector C1381c. PCM is located at left rear of engine compartment. Measure resistance between upper generator connector terminal No. 1 (Light Green/Red wire) and PCM connector C1381c terminal No. 1, and between generator connector terminal No. 1 (Light Green/Red wire) and ground. See Fig 1 and Fig 2 . Is the resistance less than 5 ohms between the generator and the PCM and greater than 10,000 ohms between the generator and ground? If yes, go to step 8. If no, repair Light Green/Red wire between upper generator and PCM or ground. See WIRING DIAGRAMS . Clear DTCs. Test system for normal operation. - Check Upper Generator Voltage
Connect upper generator connector. Connect PCM harness connector. Disconnect lower generator 3-pin connector. Start engine and let idle. Wait 2 minutes (until glow plugs turn off). Measure voltage between primary battery terminals. Is the voltage greater than 13 volts? If yes, go to next step. If no, replace upper generator. See GENERATOR (UPPER) under REMOVAL & INSTALLATION. - Check Upper Generator Output
Perform load and no-load tests on upper generator. See GENERATOR LOAD TEST and GENERATOR NO-LOAD TEST under ON-VEHICLE TESTING. Is the upper generator okay? If yes, system is operating properly at this time. If no, replace upper generator. - Check For Correct PCM Operation
Inspect PCM connector for corrosion and pushed out pins. Connect PCM connector, ensuring it is connected properly. Connect all disconnected connectors. Operate system. Is the concern still present? If yes, replace PCM. If no, system is operating properly at this time.