P2049 code meaning
Reductant Injection Valve Circuit High (Bank 1 Unit 1)
Powertrain system Generic code P20xx codes Check engine light
What P2049 means
P2049 is the opposite electrical case for the Bank 1, unit 1 DEF injector: the low-side control line sees battery voltage, for instance through contact with a powered conductor or water inside the connector. On the 2014 Cruze diesel GM rates it Type B (two trips), whereas the LML and the 2018 diesel tables treat it as Type A; the 2018 test needs more than 11 V and counts 30 bad samples out of 60 at 100 ms. Deutz lists it for the EMR5 metering unit as an over-normal voltage or high-side short, and Ford's 2023 summary gives an injector current below 0.1 A as the trigger. GM's DEF bulletin sorts P2049 among non-tamper faults, so it brings up the emission service message rather than the tamper warning. The output stage shuts off to protect itself, which stops dosing.
P2049 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2049
- MIL on (on some GM diesels only after the second trip)
- Service emission system message
- Higher NOx because no DEF is injected
Common causes of P2049
- Most likelyControl wire shorted to a supply wire in the harness
- PossibleMoisture or corrosion bridging pins at the injector connector
- PossibleInternal fault of the DEF injector coil
- Less likelyDefective output stage in the control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Reductant injection valve
What each part of P2049 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| 49 | The exact fault in that area. |
What to do next
- Note P2049 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2049
What does P2049 mean?
P2049 means "Reductant Injection Valve Circuit High (Bank 1 Unit 1)". P2049 is the opposite electrical case for the Bank 1, unit 1 DEF injector: the low-side control line sees battery voltage, for instance through contact with a powered conductor or water inside the connector. It is a generic code, so it means the same on every make.
Is it safe to drive with P2049?
Drive gently and only to a workshop. With P2049 the car can go into limp mode (reduced power) to protect itself.
Will P2049 fail an emissions test?
Yes, it can. P2049 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2049 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2049 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.