B368 B368 bypass valve: symptoms, fault codes and OEM cross references.
B368 bypass valve data is reported in several ways: fuel bypass, wastegate/bypass valve and EGR cooler bypass actuator. The lookup page should therefore make the ambiguity visible and route users by fault code and symptom.
OEM report needs verification
This number appears in duplicated or conflicting report groups. Confirm by VIN, engine type, installed connector and photos before quoting or fitting.
- The source reports conflict on the exact B368 subsystem. Keep multiple matches visible by symptoms and P-codes.
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.
Reduced motor power and lazy spool-up
Truck smokes more on hard acceleration
Boost comes and goes instead of building cleanly
Cold-start warm-up takes too long
Coolant temperature slow to rise
Engine protection during DPF regeneration attempt
Why B368 usually fails
- Thermal degradation of solenoid coil insulation causing short to ground or supply.
- Bypass flap seizes from soot, condensate corrosion or rod corrosion.
- Motor gear-train wear on EGR cooler bypass operation.
- Wiring short to ECU output in the bypass actuator circuit.
Before replacing the part
- Use the fault code family to decide whether the customer is describing fuel-pressure bypass or EGR cooler bypass.
- Inspect harness continuity and short-to-ground before replacing the valve.
P-codes reported with B368.
| Code | Lookup hint | Related symptom area |
|---|---|---|
| P0234 | Overboost condition or stuck wastegate / control problem | Reduced motor power and lazy spool-up |
| P0243 | Bypass / wastegate solenoid control circuit | Reduced motor power and lazy spool-up |
| P0245 | Bypass / wastegate solenoid low or short-to-ground report | Reduced motor power and lazy spool-up |
| P0246 | Bypass / wastegate solenoid high or short-to-supply report | Reduced motor power and lazy spool-up |
| P140F | EGR bypass / cooler bypass plausibility report code | Reduced motor power and lazy spool-up |
| P1457 | EGR cooler bypass or aftertreatment support report code | Reduced motor power and lazy spool-up |
| P1458 | EGR cooler bypass report code | Reduced motor power and lazy spool-up |
| P145D | EGR cooler bypass actuator report code | Reduced motor power and lazy spool-up |
Truck, engine and year ranges from the reports.
| Truck model | Engine | Years | HP |
|---|---|---|---|
| XF 105 | MX-13 Euro 4/5 | 2006-2013 | 410-510 |
| CF 85 | MX-13 Euro 4/5 | 2006-2013 | 410-510 |
| XF 106 | MX-11 / MX-13 Euro 6 | 2013-2023 | 320-530 |
| CF 480 / CF 530 | MX-13 Euro 6 | 2017-2023 | 480-530 |
Fitment is structured from user-provided reports and must be verified by VIN, installed connector and physical part markings before supply.
Questions about B368.
What are common failure symptoms for B368?
Common symptoms include Reduced motor power and lazy spool-up; Truck smokes more on hard acceleration; Boost comes and goes instead of building cleanly; Cold-start warm-up takes too long. Exact symptoms vary by truck, software level and related faults.
Which fault codes are linked with B368?
Reported fault codes include P0234, P0243, P0245, P0246, P140F, P1457, P1458, P145D.
Can I order by OEM number B368 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.
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