U3003: Battery Voltage
What Does U3003 Mean?
U3003 is a diagnostic trouble code indicating: Battery Voltage. This code relates to the network manufacturer-specific system. It has been reported in NHTSA complaints across 7 different vehicle models.
Symptoms of U3003
- ⚠️ Engine misfires
- ⚠️ Loss of engine power
- ⚠️ Transmission slipping
- ⚠️ Steering issues
Common Causes
- 🔍 Worn or fouled spark plugs
- 🔍 Failed ignition coil
- 🔍 Wiring or connector problem
- 🔍 Turbocharger or boost system issue
- 🔍 Sensor or control module malfunction
U3003 Reports by Year
Real Owner Reports
From NHTSA complaint database — actual owner descriptions.
"Began getting several alerts, when taken in to get a diagnosis I received the following error codes P0301, P0304, P0301, P0300, U0401-68 & U3003-16. These codes stated that I had Cylinder 1 Misfire, Cylinder 4 Misfire as well as Random Misfire and ECM Failure and Electric Parking Brake Control Unit "
— Honda Accord owner, 12/04/2023
"Car was not able to shift into lower gears. Car would not accelerate when put in drive and drive did not illuminate on the dash. Gearshift was slipping between neutral and drive. mechanic got code of U3003–16. And U 04168. On a separate couple of occasions, the emergency brake system was activated w"
— Honda Cr-V owner, 04/18/2025
"2018 CR-V (~38,200 MILES) UNEXPECTEDLY HALTED (LOSS OF POWER - ENGINE KEPT RUNNING) GOING ~35 MPH ON LAKEVILLE HWY/116 IN BUSY TRAFFIC AND SHOWED ENGINE/EMISSIONS CHECK LIGHT AND OTHER WARNING LIGHTS. TOWED TO DEALER WHERE DIAGNOSTIC CODES P061B ECM/PCM INTERNAL MALFUNCTION (TORGUE CALCULATION), C18"
— Honda Cr-V owner, 07/29/2020
Source: NHTSA Complaints Database
Most Reported Vehicles for U3003
Based on NHTSA owner complaint data.
| # | Vehicle | Reports |
|---|---|---|
| 1 | HONDA ACCORD | |
| 2 | FORD FUSION | |
| 3 | HONDA CR-V | |
| 4 | FORD EXPLORER | |
| 5 | FORD FOCUS | |
| 6 | FORD RANGER | |
| 7 | FORD ESCAPE |
U3003 Reports by Vehicle
Detailed NHTSA complaint analysis for each vehicle model.
Frequently Asked Questions
Can I drive with this code?
Will this code clear itself?
How do I find the exact cause?
What To Do Next
Possible Fixes
- 🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
- 🔧 Test the relevant sensor(s) with a multimeter before replacing
- 🔧 Inspect wiring harness and connectors for damage, corrosion, or loose connections
- 🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)
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1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
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2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
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3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.