X11 CM2670 — Engine Introduction
Complete overview of the Cummins X11 CM2670 X126B heavy-duty diesel engine. Covers engine specifications, XPI high-pressure common rail fuel system, VGT turbocharger, EGR system, and system architecture for NS VI / Euro VI compliance.
ENGINE OVERVIEW
Engine Identity
The Cummins X11 CM2670 X126B is a heavy-duty inline 6-cylinder diesel engine with 10.8 L displacement, designed for automotive (bus and truck) applications. It meets NS VI / Euro VI emission standards through advanced combustion optimization combined with a full aftertreatment system.
Key Systems
High-pressure common rail, up to 2000 bar. Gear pump + HP pump + 6 solenoid injectors.
Variable geometry turbo with PWM actuator. Compressor inlet P/T sensor.
Stepper-motor EGR valve, EGR cooler, exhaust throttle for thermal management.
DOC + DPF + SCR + ASC. UL2.2 DEF dosing. 97% DeNOx efficiency.
96-pin OEM (J2) + 96-pin engine (J1). 4x SAE J1939 data links. INSITE v8.5+.
ENGINE SPECIFICATIONS
| PARAMETER | SPECIFICATION | NOTES |
|---|---|---|
| Engine Family | X-Series (X11) | 11-liter class |
| Displacement | 10.8 L | Inline 6-cylinder |
| Emission Standard | NS VI / Euro VI | Full aftertreatment required |
| Fuel System | XPI Common Rail | Up to 2000 bar rail pressure |
| Turbocharger | VGT | PWM-controlled actuator |
| EGR Type | Cooled EGR | Stepper motor valve |
| Aftertreatment | DOC + DPF + SCR + ASC | UL2.2 DEF dosing |
| ECM | CM2670D | 2x 96-pin connectors |
| Data Links | 4x SAE J1939 | 2 public + 2 private |
| Cam Sensor | Hall-effect | 6+1 tooth pattern |
| Crank Sensor | Hall-effect | 60-2 tooth pattern |
| Firing Order | 1-5-3-6-2-4 | Overhead adj. marks A-F |
| Service Tool | INSITE v8.5+ | J1939 communication |
| Wiring Diagram | PN 5504467 | X11 CM2670 X126B |
| Fault Code Manual | PN 5504466 | X11 CM2670 X126B |
| Service Manual | PN 5504465 | X11 CM2670 X126B |
XPI FUEL SYSTEM
VGT TURBOCHARGER
Variable Geometry
Adjustable vane nozzle ring controls exhaust flow to turbine wheel
PWM-Controlled
ECM commands position based on load, speed, altitude
Compressor Inlet P/T
OEM-provided, mounted after air filter. TMAP on intake manifold.
EGR SYSTEM
Stepper Motor
Precise position control for EGR flow rate regulation
Coolant-Cooled
Reduces recirculated exhaust temperature before intake
Thermal Management
Closes to raise exhaust temp for DPF regeneration
SYSTEM ARCHITECTURE
SERVICE INFORMATION
Documentation
Use QuickServe Online with ESN (Engine Serial Number) for model-specific service data lookup. Dataplate located on rocker lever cover.
Diagnostic Tools
QUICK REFERENCE TABLE
| PARAMETER | EXPECTED VALUE | FAULT INDICATION |
|---|---|---|
| Engine Displacement | 10.8 L | N/A |
| Configuration | Inline 6-cylinder | N/A |
| Emission Standard | NS VI / Euro VI | N/A |
| ECM Model | CM2670D | N/A |
| Rail Pressure (Idle) | 350-500 bar | < 300 bar |
| Rail Pressure (Rated) | 1400-2000 bar | < 1200 bar |
| Cam Sensor Pattern | 6+1 teeth | Missing pulses |
| Crank Sensor Pattern | 60-2 teeth | Missing pulses |
| Firing Order | 1-5-3-6-2-4 | N/A |
| Oil Pressure Switch | Opens 48-62 kPa | No switch |
| INSITE Version Required | v8.5+ | Older versions |
| J1939 Data Links | 4 channels | < 4 active |
| ECM Connectors | J1 (96-pin) + J2 (96-pin) | Damaged pins |
| Wiring Diagram PN | 5504467 | N/A |
| Fault Code Manual PN | 5504466 | N/A |
| Service Manual PN | 5504465 | N/A |
DOC, DPF, SCR, ASC, UL2.2 DEF dosing
ECM, sensors, actuators, fault codes
Overhead adjustment, INSITE tests