B134 B134 pump unit valve cyl 4: symptoms, fault codes and OEM cross references.
Cylinder 4 unit pump solenoid group for DAF DMCI/EUP systems. Focuses on cylinder 4 misfire, P0204/P0270/P0271 fault code searches and high-mileage solenoid failures.
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.
Cylinder 4 diesel knock under acceleration
Jerky pull from 900 to 1200 rpm
Cylinder 4 contribution too low
Engine derate or power reduction
Hard starting after heat soak
Why B134 usually fails
- Open or short circuit on cylinder 4 ECU/pump wiring.
- Coil winding insulation breakdown.
- Pump unit cylinder 4 internal seizure or sticking control valve.
- Metal debris from lift-pump wear damaging unit pump elements.
Before replacing the part
- Check fuel contamination and pump debris if more than one cylinder pump fault appears.
- Record cylinder contribution data before parts are removed.
P-codes reported with B134.
| Code | Lookup hint | Related symptom area |
|---|---|---|
| P0204 | Cylinder 4 injector or pump-unit control circuit | Cylinder 4 diesel knock under acceleration |
| P0270 | Cylinder 4 pump/injector control circuit low | Cylinder 4 diesel knock under acceleration |
| P0271 | Cylinder 4 pump/injector control circuit high | Cylinder 4 diesel knock under acceleration |
| P0272 | Cylinder 4 contribution / balance issue | Cylinder 4 diesel knock under acceleration |
| P1233 | Cylinder 4 pump-unit contribution / control report | Cylinder 4 diesel knock under acceleration |
| P1250 | Cylinder 4 pump-unit report code | Cylinder 4 diesel knock under acceleration |
| P2150 | Injector/pump-unit group supply low or short report | Cylinder 4 diesel knock under acceleration |
| P2151 | Injector/pump-unit group supply high or short report | Cylinder 4 diesel knock under acceleration |
All numbers grouped under the canonical B134 page.
Keeping every duplicate and replacement number visible on the same canonical page helps exact OEM searches without creating hundreds of duplicated pages.
Truck, engine and year ranges from the reports.
| Truck model | Engine | Years | HP |
|---|---|---|---|
| XF 95 | PACCAR XE/MX Euro 3 | 2001-2006 | 380-530 |
| XF 105 | PACCAR MX Euro 3/4/5 | 2005-2013 | 360-510 |
| CF 75 | PACCAR PR Euro 3/4/5 | 2001-2013 | 250-360 |
| CF 85 | PACCAR MX Euro 3/4/5 | 2001-2013 | 340-510 |
Fitment is structured from user-provided reports and must be verified by VIN, installed connector and physical part markings before supply.
Questions about B134.
What are common failure symptoms for B134?
Common symptoms include Cylinder 4 diesel knock under acceleration; Jerky pull from 900 to 1200 rpm; Cylinder 4 contribution too low; Engine derate or power reduction. Exact symptoms vary by truck, software level and related faults.
Which fault codes are linked with B134?
Reported fault codes include P0204, P0270, P0271, P0272, P1233, P1250, P2150, P2151.
Can I order by OEM number B134 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
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