U013E code meaning
Lost Communication With Vacuum Sensor B
Network system Generic code U01xx codes Check engine light
What U013E means
U013E concerns vacuum sensor B, the second networked vacuum sensor in vehicles that measure at more than one point, for example in the booster chamber and in a separate reservoir, or that read a redundant value. The receiving module, typically the engine or brake controller, sets the code when the frames of this sensor stop arriving. No manufacturer has published a description of U013E, and public sources do not reveal which vehicles carry two bus vacuum sensors. For orientation: GM's ECM tables cover the analog booster pressure sensor with P0556 to P0558, and CARB requires lost communication from a digital input to get its own code. U013D is sensor A, U043F invalid data from sensor B. Similar effects to U013D are likely.
U013E at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U013E
- Brake system or brake assist warning
- Often stored together with U013D when both sensors share wiring
Common causes of U013E
- Most likelyLoose or corroded connector at vacuum sensor B
- PossibleSupply, ground or bus wiring shared with sensor A faulty
- Less likelyVacuum sensor B internally faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Vacuum sensor bCAN bus wiring
What each part of U013E means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 3E | The exact fault in that area. |
What to do next
- Note U013E 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 U013E
What does U013E mean?
U013E means "Lost Communication With Vacuum Sensor B". U013E concerns vacuum sensor B, the second networked vacuum sensor in vehicles that measure at more than one point, for example in the booster chamber and in a separate reservoir, or that read a redundant value. It is a generic code, so it means the same on every make.
Is it safe to drive with U013E?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will U013E fail an emissions test?
Yes, it can. U013E is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is U013E to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will U013E clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.