The PACCAR MX injector P1223 fault code diagnostic manual is the official 2013 service document covering cylinder 4 injector solenoid valve voltage and short circuit faults on EPA-compliant MX engines. Published by PACCAR for truck mechanics and workshop technicians, this 5-page guide provides complete electrical schematics, component specifications, and step-by-step troubleshooting procedures.
Fault code P1223 indicates either low voltage on the injector solenoid (less than 20% of threshold) or insufficient current through the driver bank sense resistor (below 4.5 A). This diagnostic references ECU connector D420 pin A12 and covers all six-cylinder fuel injector circuits via connectors B460 and B461.
Document details and specifications — PACCAR MX injector
| Brand | PACCAR |
| Model coverage | MX Engines (EPA 2013) |
| System/Group | DTCs / MX Engines (EPA2013) |
| Publication number | P1223 |
| Year/Revision | 2013 |
| Pages | 5 |
| File size | 0.4 MB |
| Format | |
| Language | English |
Table of contents
- Fault code P1223 description and information
- Component description: fuel injector solenoid valve operation and control
- Injector calibration codes and reprogramming requirements
- Electrical diagrams: D420 ECU connector, B460/B461 injector connectors
- Pin assignments and wiring functions (cylinders 1–6)
- Technical data: component resistance checks (0.67 Ω at 20°C, max 0.94 Ω at 120°C)
- Diagnostic set and reset conditions
- Step-by-step troubleshooting procedure
- Verification drive cycle instructions
Applies to these models
This PACCAR MX injector P1223 manual applies to 2013 EPA-compliant PACCAR MX engines with fuel injection systems. Covers diagnostic procedures for cylinder 4 solenoid valve circuits on trucks using PCI ECU control modules. For complete technical support, visit PACCAR official website.
Who needs this MX injector P1223 manual
Diesel mechanics, truck technicians, and workshop owners diagnosing fuel injector electrical faults on 2013 PACCAR MX engines need this manual. Essential for identifying voltage losses, short circuits, and solenoid driver bank failures that trigger MIL warnings and reduced engine performance.
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