PACCAR MX P103C is the diagnostic trouble code documented on this 6 pages extract from the 2013 PACCAR MX Diagnostic Service Manual, published by PACCAR for EPA2013 MX engines. PACCAR prints the fault as “EGR control – unable to reach target”, in the manual’s standard fault code layout.
Document details for PACCAR MX P103C
| Brand | PACCAR |
|---|---|
| Model coverage | PACCAR MX engines, EPA2013 emissions level |
| System / group | DTCs / MX Engines (EPA2013) |
| Source publication | 2013 PACCAR MX Diagnostic Service Manual |
| Fault code | P103C — EGR control – unable to reach target |
| Pages | 6 |
| File size | 0.5 MB |
| Format | |
| Language | English |
Fault code summary and monitor data
The manual lists 2 trip MIL with 3 drive cycle recovery, no readiness group and a generic freeze frame type. The diagnostic runs with the engine at steady load and coolant temperature above 50 C.
- Code number
- Fault code description
- Fault code information
- Description of component(s)
- Set condition of fault code
- Reset condition of fault code
- Possible causes
- Diagnostic Step-by-Step
- Verification Drive Cycle
Component and system background
The EGR module consists of an actuator and an EGR valve whose task is to control EGR flow to the inlet manifold. The manual is explicit that valve position does not by itself indicate flow: the amount of gas fed back depends mainly on the pressure difference between pressure before turbine and boost pressure, in combination with valve position.
Set and reset conditions for PACCAR MX P103C
The code is set when the PCI ECU (D420) detects that the demanded NOx conversion is limited by the EGR system limits for more than 300 seconds. Listed causes are a leaking EGR system, a clogged EGR system and a clogged EGR pressure difference sensor venturi. Validation calls for a level grade road under load with a trailer, or engine load produced another way, after the coolant reaches at least 70 C.
Applies to EPA2013 MX engines
The PACCAR MX P103C entry sits in the DTCs / MX Engines (EPA2013) section, so it applies to PACCAR MX engines built to that emissions level. Manufacturer product information is published on the PACCAR corporate website.
Who needs the PACCAR MX P103C fault code page
Technicians reading a live code, foremen writing an estimate and fleet managers deciding whether a truck stays in service all need the manufacturer wording rather than a generic code list.
The full PDF for MX P103C is in the DiagTechPro manuals library; a free account is required to download it.
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