U064E code meaning
Lost Communication With EGR Cooler Bypass Position Sensor Bank 1
Network system Generic code U06xx codes Check engine light
What U064E means
Many diesels steer recirculated exhaust around the EGR cooler while the engine is cold and through it once warm, using a bypass flap with its own position sensor. CARB 1968.2 (f)(6.2.5) requires the cooler system to be checked for poor cooling, and that check only makes sense if the controller knows the flap position. U064E is set when this sensor on bank 1 is a digital part and its data no longer arrives. No manufacturer documents U064E publicly, and the published code lists show no separate bank 2 counterpart. An analog sensor would report P2492 to P2496 instead, and a learned end stop outside its limit is P24C4. While the position is unknown, the cooler performance monitor cannot run; warm-up emissions may rise slightly.
U064E 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 U064E
- MIL on
- EGR cooler monitor not completed
- Usually no change in driving behaviour
Common causes of U064E
- Most likelyWiring to the cooler bypass actuator damaged by heat or vibration
- PossibleCorroded or loose connector at the bypass actuator
- PossiblePosition sensor in the bypass actuator 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 cooler bypass position sensor bank 1Vehicle bus wiring
What each part of U064E means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 4E | The exact fault in that area. |
What to do next
- Note U064E 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 U064E
What does U064E mean?
U064E means "Lost Communication With EGR Cooler Bypass Position Sensor Bank 1". Many diesels steer recirculated exhaust around the EGR cooler while the engine is cold and through it once warm, using a bypass flap with its own position sensor. It is a generic code, so it means the same on every make.
Is it safe to drive with U064E?
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 U064E fail an emissions test?
Yes, it can. U064E 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 U064E to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U064E clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.