BMW DTC P21CE – Reductant Quality Module Performance
DTC P21CE meaning on BMW
The DTC P21CE code on a BMW indicates an issue with the Reductant Quality Module Performance. This module is responsible for monitoring the quality of the diesel exhaust fluid (DEF) used in the selective catalytic reduction (SCR) system.
BMW DTC P21CE symptoms
Symptoms of the DTC P21CE code on a BMW may include:
- Check Engine Light illuminated
- Reduced engine performance
- Increased fuel consumption
- Difficulty starting the vehicle
BMW DTC P21CE causes
Common causes of the DTC P21CE code on a BMW include:
- Contaminated or low-quality DEF
- Malfunctioning Reductant Quality Module
- Wiring or connection issues
BMW DTC P21CE seriousness
The DTC P21CE code should not be ignored as it can lead to increased emissions, reduced fuel efficiency, and potential damage to the SCR system. It is recommended to address this issue promptly to prevent further complications.
How to diagnose DTC P21CE on BMW
To diagnose the DTC P21CE code on a BMW, a mechanic may perform the following steps:
- Use a diagnostic scanner to retrieve the fault codes
- Inspect the DEF tank and fluid quality
- Check the Reductant Quality Module for any visible damage
- Inspect wiring and connections related to the module
How to fix DTC P21CE on BMW
To fix the DTC P21CE code on a BMW, the following steps may be taken:
- Replace the contaminated DEF with a high-quality fluid
- Repair or replace the Reductant Quality Module if faulty
- Repair any damaged wiring or connections
- Clear the fault codes and reset the Check Engine Light
How to erase DTC P21CE on BMW
To erase the DTC P21CE code on a BMW, a diagnostic scanner can be used to clear the fault codes stored in the vehicle’s computer. Once the issue has been addressed and fixed, the codes can be cleared to reset the system and turn off the Check Engine Light.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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