U3013 code meaning
Control Module Input Power C Circuit/Open
What U3013 means
U3013 extends the input power family to a third feed, C, and reports it as missing or open. It only exists on modules with at least three separately fused supplies, such as large body or brake units. No manufacturer documents U3013 publicly, and nothing defines which pin is C; that is up to each maker's wiring. The detection principle can be taken from GM's brake module, which compares two battery feeds and flags one as open when it drops to about half of the other for 75 ms (U3006/U3007). CARB requires electronic inputs that the OBD system relies on to be checked for circuit faults, which is the basis for such checks. In practice a single blown fuse, a pushed-out pin or a weak battery is behind it; if C and D appear together, look for a shared fuse or a supply common to both.
U3013 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U3013
- Part of the functions of the affected module dead
- Lost communication codes in other modules if the unit shuts down
Common causes of U3013
- Most likelyBlown fuse in the feed C path
- PossiblePushed-out pin, corroded terminal or broken wire on supply C
- PossibleWeak battery or voltage dip during cranking
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Module power cFuse
What each part of U3013 means
| U | Network system: communication between the control modules (CAN bus). |
| 3 | Reserved range, usually generic. |
| 13 | The exact fault in that area. |
What to do next
- Note U3013 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U3013
What does U3013 mean?
U3013 means "Control Module Input Power C Circuit/Open". U3013 extends the input power family to a third feed, C, and reports it as missing or open. It is a generic code, so it means the same on every make.
Is it safe to drive with U3013?
U3013 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U3013 fail an emissions test?
U3013 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U3013 to fix?
Difficulty: medium. A typical repair takes 0.3 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will U3013 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.