B411 B411 engine brake solenoid cyl 1: symptoms, fault codes and OEM cross references.
Cylinder 1 MX engine brake solenoid group. Searches usually combine B411 with P3405, P3407 or complaints about weak engine braking.
What drivers and mechanics usually notice.
These are practical, workshop-style symptom phrases written for search and support conversations. They are not a substitute for live diagnostic data.
MX engine brake retard force reduced
Engine brake loses one stage and feels weak
DAVIE4 actuation test on brake cylinder 1 fails
Uneven engine brake noise on overrun
Engine warning lamp appears when engine brake is applied
Why B411 usually fails
- Open circuit on ECU output or short to ground.
- Engine brake cylinder 1 solenoid coil burn-out.
- Valve clearance or mechanical pusher issue on the rocker shaft.
- Varnish or oil contamination creates sticky valve movement.
Before replacing the part
- Test engine brake solenoid operation when oil is hot because some coil faults are intermittent.
- Inspect rocker-cover harness for open circuits before replacing the solenoid.
P-codes reported with B411.
| Code | Lookup hint | Related symptom area |
|---|---|---|
| P3405 | Cylinder 1 engine-brake solenoid control circuit/open report | MX engine brake retard force reduced |
| P3406 | Cylinder 1 engine-brake solenoid performance report | MX engine brake retard force reduced |
| P3407 | Cylinder 1 engine-brake solenoid short-to-ground report | MX engine brake retard force reduced |
| P3408 | Cylinder 1 engine-brake solenoid electrical report | MX engine brake retard force reduced |
Truck, engine and year ranges from the reports.
| Truck model | Engine | Years | HP |
|---|---|---|---|
| XF 105 | PACCAR MX Euro 3/4/5 | 2005-2013 | 360-510 |
| XF 106 | MX-11 / MX-13 Euro 6 | 2013-2023 | 320-530 |
| CF 85 | PACCAR MX Euro 3/4/5/6 | 2005-2022 | 340-530 |
| CF 430 / CF 480 / CF 530 | MX Euro 6 | 2017-2023 | 430-530 |
Fitment is structured from user-provided reports and must be verified by VIN, installed connector and physical part markings before supply.
Questions about B411.
What are common failure symptoms for B411?
Common symptoms include MX engine brake retard force reduced; Engine brake loses one stage and feels weak; DAVIE4 actuation test on brake cylinder 1 fails; Uneven engine brake noise on overrun. Exact symptoms vary by truck, software level and related faults.
Which fault codes are linked with B411?
Reported fault codes include P3405, P3406, P3407, P3408.
Can I order by OEM number B411 only?
Use the OEM number as a starting point, then confirm by VIN, engine type, installed connector and part photos because some reports contain duplicate or conflicting OEM references.
More fuel / brake / bypass valve lookups
B368 bypass valve
Reduced motor power and lazy spool-up · Truck smokes more on hard acceleration
B131 pump unit valve cyl 1
Engine misfire on cylinder 1 · Rough idle and vibration
B132 pump unit valve cyl 2
Cylinder 2 misfire and vibration at idle · Torque contribution from cylinder 2 too low
Ready for a quote?
Reply by email or WhatsApp. No deposit, no obligation.
Direct references from fleet operators in your country — available on request.