Powertrain, generic (extended)

P2049 Reductant Injection Valve Circuit High (Bank 1 Unit 1)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

Control wire shorted to a supply wire in the harness
Moisture or corrosion bridging pins at the injector connector
Internal fault of the DEF injector coil
Defective output stage in the control module

Symptoms

  • MIL on (on some GM diesels only after the second trip)
  • Service emission system message
  • Higher NOx because no DEF is injected

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–900
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

reductant injection valve

Related codes

P2047P2048P2052P2055

References: gsi.ext.gm.com, gsi.ext.gm.com, serdia.deutz.com, fordservicecontent.com.