Pinpoint Test I: DTC U3003:17

High-Voltage Converter/Inverter

Pinpoint Tests






Pinpoint Test I: DTC U3003:17

Refer to Wiring Diagram Set 12 (Fusion/Milan/MKZ, Fusion Hybrid/Milan Hybrid), Charging System for schematic and connector information. Diagrams By Number

Normal Operation

The DC to DC Converter Control Module (DC/DC) monitors the 12-volt battery system voltage internally at the B+ terminal of the DC/DC. If the voltage is greater than 16 volts, the DC/DC sets DTC U3003:17 and requests CHECK CHARGING SYSTEM be displayed in the message center. The DC/DC will be in standby mode (DC/DC disabled) and the 12-volt battery will eventually be drained. Reduced or no functionality of 12-volt systems (headlamps, HVAC blower motor, etc.) may also be noticed.

- DTC U3003:17 (Battery Voltage: Circuit Voltage Above Threshold) - Sets if the 12-volt battery system voltage is greater than 16 volts.

This pinpoint test is intended to diagnose the following:
- 12-volt battery jump started or incorrectly charged
- Customer-installed accessory
- DC/DC



PINPOINT TEST I: DTC U3003:17

-------------------------------------------------
I1 CHECK VOLTAGE AT THE DC/DC


- Start the engine.
- Turn off the headlamps, blower and any other accessories.
- Measure the voltage of the battery.




- Is the voltage less than 16 volts?

Yes
GO to I2.

No
GO to I3.

-------------------------------------------------
I2 TEST BATTERY CONDITION


- Ignition OFF.
- Carry out the battery condition test. Refer to Battery. Pinpoint Tests
- Did the battery pass the condition test?

Yes
GO to I4.

No
DTC U3003:17 was most likely set due to the 12-volt battery being recently jump started or incorrectly charged using a battery charger. INSTALL a new battery. CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation. If DTC U3003:17 is still present, GO to I3.

-------------------------------------------------
I3 INSPECT VEHICLE ACCESSORIES


- Ignition OFF.
- Inspect the vehicle and disable any customer installed accessories.
- Start the engine.
- Measure the voltage of the battery.




- Is the voltage less than 16 volts?

Yes
COMMUNICATE the accessory concern to the customer. CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation.

No
GO to I4.

-------------------------------------------------
I4 CLEAR DTCs AND CARRY OUT SELF-TEST OF THE DC/DC


- Ignition ON.
- Connect the scan tool.
- Using the scan tool, clear the DC/DC DTCs.
- Enter the following diagnostic mode on the scan tool: Self Test - DC/DC.
- Is DTC U3003:17 reported?

Yes
INSTALL a new DC/DC. REFER to Direct Current/Direct Current (DC/DC) Converter . REPEAT the self-test.
TEST the system for normal operation.

No
Concern is not present at this time. DTC U3003:17 was most likely set due to the 12-volt battery being recently jump started or incorrectly charged using a battery charger. CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation.

-------------------------------------------------