P249D on 2018-2019 Chevrolet Equinox (LT, Premier) — Closed Loop Reductant Injection Control At Limit - Flow Too Low
1 vehicles · 1 makes · $350-$1,500 repair
Most Reported On
P249D is an OBD-II diagnostic trouble code meaning “Closed Loop Reductant Injection Control At Limit - Flow Too Low.” Generic diesel SCR code indicating the closed-loop reductant (DEF) injection control has reached its adjustment limit because DEF flow is too low. The PCM is commanding more DEF than the system can deliver, so NOx cannot be adequately reduced. This code is most commonly reported on 2018-2019 Chevrolet Equinox (LT, Premier), with repair costs ranging from $350 to $1,500.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P249D, 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
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FAQ
What does P249D mean?
P249D stands for "Closed Loop Reductant Injection Control At Limit - Flow Too Low." Generic diesel SCR code indicating the closed-loop reductant (DEF) injection control has reached its adjustment limit because DEF flow is too low. The PCM is commanding more DEF than the system can deliver, so NOx cannot be adequately reduced.
What are the most common causes of P249D?
The most common causes of P249D are: Clogged or restricted DEF injector, Weak DEF supply/metering pump, Restricted DEF lines or filter, Low DEF level or poor DEF quality, Failing NOx sensor skewing the feedback loop. The specific cause varies by vehicle.
How much does it cost to fix P249D?
Repair costs for P249D range from $350 to $1,500, depending on the vehicle and root cause.
Which vehicles are affected by P249D?
Au7o has documented P249D across 1 vehicle models from 1 manufacturers: Chevrolet.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.