P189C: Diesel Particulate Filter Restriction - Forced Limited Power
19 vehicles · 4 makes
P189C is an OBD-II diagnostic trouble code meaning “Diesel Particulate Filter Restriction - Forced Limited Power.” The diesel particulate filter is excessively restricted, triggering forced power reduction. Common on diesel trucks. This code appears across 19 vehicle models from 4 manufacturers.
Common Causes
Diagnostic Tools
To diagnose P189C, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (19)
S-Tronic Mechatronic Unit and Clutch Pack Failure
S-Tronic/DSG Mechatronic Unit Failure
S-Tronic (DSG) Mechatronic Unit Issues
S tronic Dual-Clutch Mechatronic Unit Failure
DQ381/DQ250 S tronic Mechatronic or Internal Transmission Fault Causing No-Drive, Jerking, or Gearbox Warning
DSG Transmission Issues (7-Speed DQ500)
Transmission Mechatronic Unit Failure (8-Speed Tiptronic)
S-Tronic DSG Transmission Issues (C7)
S-Tronic (DSG) Dual-Clutch Transmission Issues
S-Tronic DSG Transmission Issues (Mk2)
DSG (DQ250/DQ381) Mechatronic Unit and Clutch Pack Failure
DSG Dual-Clutch Transmission Mechatronic Unit Failure
DSG Transmission Shudder and Rough Shifting
DSG Mechatronic Unit Failure
DSG (DQ250) Transmission Failure and Mechatronic Unit Issues
7-Speed DSG (DQ381) Shudder and Rough Low-Speed Shifting
DSG Mechatronic Unit Failure
DSG Mechatronic Unit Failure
FAQ
What does P189C mean?
P189C stands for "Diesel Particulate Filter Restriction - Forced Limited Power." The diesel particulate filter is excessively restricted, triggering forced power reduction. Common on diesel trucks.
What are the most common causes of P189C?
The most common causes of P189C are: Excessive soot accumulation, Failed DPF regeneration, Faulty DPF pressure sensor, EGR system malfunction, Frequent short trips preventing regen. The specific cause varies by vehicle.
How much does it cost to fix P189C?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by P189C?
Au7o has documented P189C across 19 vehicle models from 4 manufacturers: Audi, BMW, Toyota, Volkswagen.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.