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
This is a powertrain code, so a basic OBD-II reader can read it. These read P249D.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple code reader for engine (P) codes on many compatible OBD-II vehicles. It does not support every vehicle or hybrid/EV application, and it does NOT read body, chassis or network codes; confirm exact-vehicle compatibility before buying.
- Read & clear engine (P) codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth scanner with a companion app that reads beyond the engine module — ABS, SRS and transmission — plus manufacturer-specific codes on many vehicles.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X V3.0 Elite OBD-II Scanner
by LAUNCH
Handheld scanner covering the 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 tablet with all-system coverage and bi-directional control, so you can command a module rather than only read it.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
What you can do yourself, and what needs a shop
Reading the code, clearing it, and watching whether it returns is a driveway job with the right scanner. These steps are not:
- Module programming or software updates — needs the manufacturer software or a J2534 pass-through with a paid subscription.
- Replacing a control module — most are VIN-programmed and immobilizer-registered, so a new one does nothing until it is coded to your car.
- Airbag/SRS component work — a stored fault can deploy a live device.
If the vehicle is still under warranty, check for an open recall or technical service bulletin before buying anything — the repair may already be covered.
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
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.