Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Pinpoint Test Q: U3003
- Refer to Wiring Diagrams Electronic Engine Controls - 2.7L
for schematic and connector information.
Normal Operation and Fault Conditions
The PCM receives voltage at all times from the BJB.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition PCM U3003:00 Battery Voltage: No Sub Type Information This DTC sets when the PCM detects lower than expected battery voltage on the voltage supply input circuit. Possible Sources
- Wiring, terminals or connectors
- Charging system concern
- Battery concern
- BJB
- PCM
- Q1 RECHECK THE BCM (BODY CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition ON.
- Using a diagnostic scan tool, clear the Diagnostic Trouble Codes (DTCs).
- Wait 10 seconds.
- Using a diagnostic scan tool, perform the BCM self-test.
Is DTC U3003 still present?
Yes GO to Q2 No The system is operating correctly at this time. The DTC may have been set due to a previous low battery voltage condition. CLEAR the DTC. - Q2 CHECK FOR CHARGING SYSTEM DIAGNOSTIC TROUBLE CODES (DTCS) SET IN OTHER MODULES
- Using a diagnostic scan tool, retrieve all Diagnostic Trouble Codes (DTCs).
Are any charging system Diagnostic Trouble Codes (DTCs) recorded?
Yes DIAGNOSE the charging system concern. REFER to: Charging System - 2.7L EcoBoost (238kW/324PS)/3.5L EcoBoost (BM) . No GO to Q3 - Q3 CHECK THE BATTERY CONDITION AND STATE OF CHARGE
- Check the battery condition and verify the battery is fully charged. REFER to: Battery .
Is the battery OK and fully charged?
Yes GO to Q4 No If the battery is discharged, DIAGNOSE the cause of the low battery condition. REFER to: Charging System - 2.7L EcoBoost (238kW/324PS)/3.5L EcoBoost (BM) . If the battery condition fails, INSTALL a new battery. REFER to: Battery . - Q4 COMPARE THE PCM (POWERTRAIN CONTROL MODULE) BATT_V_INF (V) PID (PARAMETER IDENTIFICATION) WITH THE ACTUAL BATTERY VOLTAGE
- Start the engine.
- Turn on accessories (climate control blower on high speed, exterior lights).
- With the engine running at idle, measure and record battery voltage:
Positive Lead Measurement / Action Negative Lead
- Access the PCM and control the BATT_V_INF (V) PID
Is the recorded battery voltage within 0.2 volt of the PID?
Yes TURN the engine off, GO to Q5 No GO to Q5 - Q5 CHECK THE PCM (POWERTRAIN CONTROL MODULE) VOLTAGE SUPPLY CIRCUITS
- Ignition OFF.
- Disconnect PCM C2280G.
- Connect a fused jumper.
Positive Lead Measurement / Action Negative Lead C1232B-74 Ground
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead C1232B-2 Ground C1232B-16 Ground C1232B-17 Ground
Are the voltages within 0.2 volt of the recorded battery voltage?
Yes GO to Q6 No REPAIR the circuit in question for high resistance. - Q6 CHECK THE PCM (POWERTRAIN CONTROL MODULE) GROUNDS
- Ignition OFF.
- Removed the fused jumper.
- Measure:
Positive Lead Measurement / Action Negative Lead C1232B-46 Ground C1232B-47 Ground C1232B-61 Ground C1232B-62 Ground C1232B-76 Ground C1232B-77 Ground
Are the resistances less than 3 ohms?
Yes GO to Q7 No REPAIR the circuit in question for high resistance. - Q7 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION
- Disconnect and inspect the PCM and all related in-line connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Reconnect all PCM and all related in-line connectors. Make sure they seat and latch correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, follow TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, Refer to PCM GUIDED ROUTINE TESTING
Internet Explorer version 11 or greater is required to perform this Pinpoint Test.No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.