U069B code meaning
Lost Communication With Exhaust Gas Temperature Sensor Bank 1 Sensor 4
Network system Generic code U06xx codes Check engine light
What U069B means
Sensor 4 is the fourth temperature point along the bank 1 exhaust. Of GM's 2025 diesel tables only 25OBDG04A contains U069A's partner U069B; 25OBDG04B ends at sensor 3. The logic is the same SENT check as for sensor 3, 19 bad samples of 25 at 100 ms after the sensor's start-up delay, Type A. What differs is the role: in the second stage of GM's hydrocarbon dosing control (P144E) EGT 4 supplies the temperature ahead of the filter, so losing it disturbs regeneration. GM rates an open or high circuit on this probe (P2471) as Type A. Ford's 2023 diesels read sensor 4 as an analog probe (P2470/P2471) and check it against the other sensors after a cold start (P246F). Sensience offers such probes with SENT or CAN output.
U069B 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 U069B
- Check engine light
- Regeneration interrupted or not started
Common causes of U069B
- Most likelyHarness to sensor 4 damaged by heat during regeneration
- PossibleSensor electronics failed
- Less likelyConnector corroded
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Egt sensor bank 1 sensor 4Vehicle bus wiring
What each part of U069B means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 9B | The exact fault in that area. |
What to do next
- Note U069B 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 U069B
What does U069B mean?
U069B means "Lost Communication With Exhaust Gas Temperature Sensor Bank 1 Sensor 4". Sensor 4 is the fourth temperature point along the bank 1 exhaust. It is a generic code, so it means the same on every make.
Is it safe to drive with U069B?
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 U069B fail an emissions test?
Yes, it can. U069B 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 U069B 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 U069B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.