U0652 code meaning
Lost Communication With EGR Sensor B
Network system Generic code U06xx codes Check engine light
What U0652 means
U0652 covers a digital EGR sensor labelled B that has stopped delivering data. What B measures depends on the maker; it may be the position of a second valve or a pressure or temperature signal of the EGR path. No manufacturer documents U0652 publicly. GM's 2025 diesel table 25OBDG04B shows how loose the lettering is: it uses U0651 for the high-pressure valve and U0653 for the low-pressure valve, whose text even calls it the B position sensor, yet U0652 does not appear at all. Sections (e)(15.2.1)(B)(i) and (f)(15.2.1)(B)(i) of the CARB rule require a separate code when a digital input stops communicating. An analog sensor B reports P0486, P0407, P0408 and P046E. Whatever B serves, its EGR function and monitor are suspended until data returns.
U0652 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0652
- MIL on
- EGR monitor incomplete
- Possibly reduced EGR operation
Common causes of U0652
- Most likelyWiring to EGR sensor B open, shorted or heat-damaged
- PossibleConnector at sensor B corroded or loose
- PossibleSensor B electronics failed
- Less likelyEngine controller input fault
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
EGR sensor bVehicle bus wiring
What each part of U0652 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 52 | The exact fault in that area. |
What to do next
- Note U0652 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 U0652
What does U0652 mean?
U0652 means "Lost Communication With EGR Sensor B". U0652 covers a digital EGR sensor labelled B that has stopped delivering data. It is a generic code, so it means the same on every make.
Is it safe to drive with U0652?
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 U0652 fail an emissions test?
Yes, it can. U0652 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 U0652 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U0652 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.