Renault Trucks AdBlue Problems
Expert diagnostics for Renault Trucks SCR systems. If your Renault Trucks has an AdBlue warning, NOx sensor fault, engine derate, or has started a restart countdown, we can help identify the root cause using dealer-level diagnostic equipment.
Common Renault Trucks SCR Faults
Renault Trucks commercial vehicles use SCR (Selective Catalytic Reduction) systems to meet Euro 5 and Euro 6 emissions standards. NOx sensors, the AdBlue dosing pump, dosing injector, and SCR catalyst are the components most commonly implicated in faults. We diagnose all fault types using dealer-level equipment and live data analysis — not code-reading alone.
NOx Sensor Faults
The upstream and downstream NOx sensors are the most common failure point on Renault Trucks trucks. They fail from soot contamination, connector corrosion, and thermal damage. A sensor fault code may also indicate wiring problems or a poorly performing catalyst rather than sensor failure — live data analysis is essential before replacing any part.
Dosing Pump Failures
The AdBlue pump must maintain correct pressure for accurate dosing. Pressure faults can result from pump wear, internal leaks, air ingestion, or blockages. Actuator testing with our diagnostic equipment measures real pump output against the expected value.
Derate & Countdown
Renault Trucks trucks implement engine derate and a "starts remaining" countdown when SCR faults reach a critical threshold. The countdown cannot be reset by clearing codes with a generic scanner — proper diagnostic access is required.
Manufacturer Diagnostic Profile
Models covered
T · C · K · D
Engine families
DTI 13 · DTI 11 · DTI 8
Diagnostic equipment
Renault Trucks Premium Tech Tool (PTT)
Terminology checked
EMS data and MID/PSID/FMI fault terminology
Volvo Renault Vocom diagnostic interface
Services
- Complete SCR Diagnostics
- NOx Sensor Testing & Wiring Checks
- AdBlue Pump Pressure Testing
- Dosing Injector Actuator Testing
- Countdown Reset (with fault resolution)
- ECU Software Verification
Vehicle Immobilised?
If your Renault Trucks has reached zero restarts, call us directly.
01302 20202907929 765432Fault Codes — Renault Trucks EMS / MID-PSID-FMI / PTT-Vocom
Common Renault Trucks AdBlue & SCR Fault Codes
MID/PSID/FMI wording identifies the controller, monitored item and failure mode. It does not establish a failed part without the associated live-data and circuit checks.
Renault Trucks applications can share diagnostic architecture with Volvo on relevant generations, but the active code must always be confirmed for the individual T, C, K or D truck.
| Fault code | System | Common description | Possible causes |
|---|---|---|---|
| MID 128 PSID 90 FMI 1 | Upstream NOx | NOx sensor error before the catalytic converter | Sensor response, circuit condition, connector or exhaust-side influence |
| MID 128 PSID 91 FMI 1 | Downstream NOx | NOx sensor error after the catalytic converter | Sensor response, wiring, exhaust leak or SCR conversion context |
| MID 128 PSID 100 FMI 1 | AdBlue level | Low AdBlue level | Fluid level, level data, wiring or tank-sensor concern |
| MID 128 PSID 106 FMI 0/1 | Dosing module | Low dosing-module performance | Pressure, supply, injector, crystallisation or module data fault |
MID 128 PSID 106 FMI 0/1
Renault Trucks MID 128 PSID 106 FMI 0/1 — dosing-module performance
What it means
The engine-management system is reporting a low-performance condition around the dosing module. The diagnosis must separate a delivery restriction from a control or sensor issue.
Common causes
- •Restricted or crystallised dosing path
- •Pump or pressure concern
- •Dosing injector condition
- •Electrical supply, connector or control-data issue
Symptoms
AdBlue warning · Emissions warning · Reduced power · Derate or restart-inducement warning
What ECUFLASH checks
ECUFLASH confirms the exact Renault Trucks code in the vehicle, reviews PTT/Vocom live data and tests the relevant pressure, dosing and electrical evidence.
Source basis: Renault Trucks failure-code manual · Existing ECUFLASH commercial-vehicle diagnostic material