Pinpoint Test H: DTC P0562 and U3003:16
High-Voltage Converter/Inverter
Pinpoint Test H: DTC P0562 and U3003:16
Refer to Wiring Diagram Set 12 (Fusion/Milan/MKZ, Fusion Hybrid, Milan Hybrid, MKZ 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 drops below 10.5 volts while the ignition is ON, the DC/DC sets DTC U3003:16 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.
The PCM monitors the system voltage through the Battery Junction Box (BJB). If this voltage drops 1.5 volts or more below the generator voltage desired, this DTC will be set after 30 seconds.
- DTC P0562 (System Voltage Low) - If the PCM detects a voltage from the charging system that is 1.5 volts lower than the DC/DC voltage desired, this DTC will be set.
- DTC U3003:16 (Battery Voltage: Circuit Voltage Below Threshold) - Sets if the 12-volt battery system voltage is less than 10.5 volts.
This pinpoint test is intended to diagnose the following:
- 12-volt battery
- 12-volt battery cables
- DC/DC
- Wiring, terminals or connectors
PINPOINT TEST H: DTC P0562 AND U3003:16
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H1 CHECK THE DC/DC DTCs
- Review the DC/DC DTCs recorded during Inspection and Verification.
- Are any DC/DC DTCs other than U3003:16 present?
Yes
REPAIR all other DC/DC DTCs before repairing U3003:16. GO to the DC to DC Converter Control Module (DC/DC) DTC Chart. DC To DC Converter Control Module (DC/DC) DTC Chart
No
GO to H2.
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H2 TEST BATTERY CONDITION
- Ignition OFF.
- Carry out the battery condition test. Refer to Battery, Mounting and Cables Testing and Inspection. Pinpoint Tests
- Did the battery pass the condition test?
Yes
GO to H3.
No
INSTALL a new battery. CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation.
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H3 CHECK VOLTAGE AT THE DC/DC
- START the vehicle (Ready Indicator light ON).
- Turn the headlamps on and the blower on high.
- Measure the voltage of the battery.
- Measure the voltage between DC/DC C1457B, circuit SDC02 (RD), harness side and DC/DC C1457C, circuit GD108 (BK/VT), harness side.
- Does the DC/DC voltage match battery voltage?
Yes
For DTC P0562, GO to H4. For DTC U3003:16, GO to H7.
No
GO to H6.
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H4 COMPARE PCM MODULE SUPPLY VOLTAGE (VPWR) PID
- With the engine still running at idle, headlamps on and blower on high, measure the battery voltage at the battery and monitor the PCM VPWR PID.
- Does PCM VPWR PID display battery voltage within ±0.5 volt?
Yes
GO to H5.
No
REPAIR high resistance or loose connections in the affected PCM power circuit(s). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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H5 CHECK PCM GROUND FOR HIGH RESISTANCE
- Monitor PCM VPWR PID.
- With the engine still running at idle, turn off all accessory loads, measure the battery voltage at the battery and note the PCM VPWR PID.
- With the engine still running at idle, turn headlamps on and blower on high, measure the battery voltage at the battery and monitor the PCM VPWR PID.
- Does the VPWR PID read within ±0.5 volt with accessory loads on as compared to accessory loads off?
Yes
GO to H7.
No
REPAIR the affected PCM ground circuits. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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H6 MEASURE VOLTAGE DROP OF DC/DC B+ CIRCUIT
- Measure the voltage between DC/DC C1457B, circuit SDC02 (RD), harness side and the positive battery terminal.
- Is the voltage drop less than 0.5 volt?
Yes
REPAIR DC/DC B- circuit GD108 (BK/VT) or INSTALL a new cable, if necessary. CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation.
No
REPAIR DC/DC B+ circuit SDC02 (RD) or INSTALL a new cable, if necessary. CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation.
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H7 CLEAR DTCs AND CARRY OUT SELF-TEST OF THE DC/DC
- 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 U3003:16 reported?
Yes
INSTALL a new DC/DC. REFER to High Voltage Traction Battery Service and Repair. CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a discharged battery. REPEAT the self-test. TEST the system for normal operation.
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