Scania XCOM 2.54 Fault Code Reference & Troubleshooting Guide
When a Scania truck’s dashboard lights up with a fault, you need more than just a code reader. Scania XCOM 2.54 working alongside a diagnostic tool gives you the complete picture: the fault code, its root cause, and the parameter-level fix. This guide covers the most common Scania fault categories you’ll encounter and how to resolve them.
How Scania Fault Codes Work
Scania fault codes follow the SAE J1939 SPN/FMI format:
- SPN (Suspect Parameter Number): Identifies the system or component (e.g., SPN 102 = Intake Manifold Pressure)
- FMI (Failure Mode Identifier): Describes the type of fault (e.g., FMI 3 = Voltage Above Normal)
- OC (Occurrence Count): How many times the fault has triggered
Scania XCOM reads fault codes from all connected ECUs simultaneously, giving you a system-wide view before you start making parameter changes.
Top 5 Scania Fault Categories & Solutions
1. AdBlue/SCR System Faults (EEC ECU)
Most common faults β especially after AdBlue delete or SCR system issues.
| SPN:FMI | Description | Root Cause | XCOM Fix |
|---|---|---|---|
| 3226:FMI 10 | AdBlue Fluid Level β Abnormal Rate of Change | Sensor fault or tank empty after delete | Disable AdBlue system in EEC parameters |
| 1761:FMI 18 | SCR Conversion Efficiency β Below Normal | Catalyst removed or degraded | Disable SCR efficiency monitoring via XCOM |
| 4334:FMI 3 | AdBlue Dosing Valve β Voltage Above Normal | Open circuit or valve failure | Disable dosing system parameter + clear DTCs |
| 5809:FMI 7 | NOx Sensor β Mechanical Failure | Sensor removed with delete kit | Disable NOx monitoring in EEC β Parameters |
XCOM Steps: EEC ECU β Parameters β AdBlue System = “OFF” β SCR Monitoring = “Disabled” β Clear DTCs
2. EGR System Faults (EMS ECU)
EGR valve sticking, carbon buildup, and post-delete fault codes.
| SPN:FMI | Description | Root Cause | XCOM Fix |
|---|---|---|---|
| 51:FMI 3 | Throttle Position β Voltage High | EGR valve stuck open | Disable EGR valve control + test valve |
| 51:FMI 4 | Throttle Position β Voltage Low | EGR valve stuck closed / carbon | EGR delete via XCOM + physical delete |
| 412:FMI 2 | EGR Temperature β Erratic | Sensor or cooler blockage | Disable EGR cooler bypass timer |
| 110:FMI 15 | Coolant Temp β Above Normal Range | EGR cooler leak | Check cooler; disable EGR if removed |
XCOM Steps: EMS ECU β Parameters β EGR Valve Control = “Deactivated” β EGR Cooler = “Bypassed” β Clear DTCs
3. Engine Performance Faults (EMS ECU)
Torque derates, power loss, and limp mode issues.
| SPN:FMI | Description | Root Cause | XCOM Fix |
|---|---|---|---|
| 520:FMI 19 | Retarder Request β Received Network Data Error | CAN bus communication issue | Check CAN wiring; verify EMS parameters |
| 190:FMI 16 | Engine Speed β Above Normal (governed) | Over-fuel condition; DPF blocked | Adjust fuel map; force DPF regen first |
| 102:FMI 3 | Intake Manifold Pressure β Voltage High | Boost leak or sensor fault | Check turbo system; reset adaptation |
| 108:FMI 3 | Barometric Pressure β Voltage High | Sensor unplugged or damaged | Replace sensor; no XCOM fix needed |
4. Transmission Faults (GMS ECU)
Shifting problems, retarder malfunctions, and clutch issues.
| SPN:FMI | Description | Root Cause | Action |
|---|---|---|---|
| 5600:FMI 5 | Clutch Actuator Current β Below Normal | Clutch worn or actuator fault | Run clutch adaptation reset in OPC4 |
| 5700:FMI 2 | Shift Cylinder Pressure β Erratic | Oil level low or solenoid issue | Check oil level; test shift solenoids |
| 5201:FMI 9 | Retarder Percent β Abnormal Update Rate | CAN communication error between RET and GMS | Check CAN bus; verify GMS parameters |
5. CAN Bus Communication Faults (COO ECU)
Network errors that affect multiple systems simultaneously.
| SPN:FMI | Description | Root Cause | Action |
|---|---|---|---|
| 639:FMI 9 | J1939 Network #1 β Abnormal Update Rate | Termination resistor failure or CAN wiring | Check 120Ξ© termination; inspect wiring |
| 1231:FMI 12 | J1939 Network #2 β Bad Device | Module offline (EMS, EEC, GMS) | Check module power/ground; reflash if needed |
| 65498:FMI 11 | Manufacturer Specific β Unknown | Parameter mismatch after ECU swap | VIN reprogram via COO ECU in XCOM |
Clearing Fault Codes with XCOM
After making parameter changes with XCOM, always clear fault codes from all ECUs:
- XCOM β System Scan β Identify all ECUs
- Select ECU β Diagnostics β DTC Read
- Select ECU β Diagnostics β DTC Clear (All)
- Cycle ignition OFF β Wait 30 seconds β Ignition ON
- Confirm codes are cleared with a fresh DTC read
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