P2049

Reductant Injection Valve Circuit High Bank 1 Unit 1

P2049 is a generic OBD-II powertrain diagnostic trouble code: Reductant Injection Valve Circuit High Bank 1 Unit 1. It is logged by the engine control unit when the scr/adblue monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P2049
Group
Powertrain
System
SCR/AdBlue
Severity
Warning (MIL on, possible limp mode)
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What P2049 means

DTC P2049 — Reductant Injection Valve Circuit High, Bank 1 Unit 1 — is an SAE generic powertrain code stored when the ECM/PCM detects that the electrical signal voltage on the control circuit of the SCR reductant (DEF/AdBlue) dosing injector for Bank 1, Unit 1 is above the expected high threshold. The reductant injection valve is responsible for precisely metering aqueous urea solution into the exhaust stream upstream of the SCR catalyst.

The 'circuit high' designation means the ECM has measured a higher-than-specified voltage — typically caused by a short to a voltage supply in the injector wiring harness, an open circuit in the low-side (return) path forcing the sense line high, or an internal injector coil failure.

The code is most common on diesel vehicles equipped with a standalone SCR dosing module (e.g., Bosch DENOXTRONIC or Continental SCR systems).

Common causes

Most-frequently reported root causes when P2049 is logged.

  • 1
    Short to voltage (B+) in the reductant injector signal or control wire
  • 2
    Open circuit on the low-side return wire of the dosing injector circuit
  • 3
    Failed or internally shorted reductant dosing injector coil
  • 4
    Corroded, damaged, or backed-out connector pins at the injector or SCR dosing module
  • 5
    Damaged wiring harness routed near hot exhaust components
  • 6
    Faulty SCR dosing control module (DCU/DENOXTRONIC unit) output driver
  • 7
    Water or DEF fluid ingress into the injector connector causing a short

Symptoms drivers notice

MIL (Check Engine light) illuminated
SCR/AdBlue system warning or DEF indicator lamp on dash
Increased NOx emissions
Possible engine torque derate or reduced performance if fault is persistent
DEF consumption may stop or become erratic
Possible DTC companions: P2048, P20EE, P207F

How to diagnose P2049

A typical diagnostic flow when this code is present.

  1. 1
    Retrieve all stored DTCs and freeze-frame data
  2. 2
    Perform a visual inspection of the reductant injector wiring harness and connector
  3. 3
    With ignition OFF, measure resistance of the dosing injector coil between its two terminals — compare to OEM spec
  4. 4
    With ignition ON (engine off), use a DMM to measure voltage on the injector control wire relative to chassis ground
  5. 5
    Disconnect the SCR dosing module (DCU) connector and recheck the injector circuit resistance
  6. 6
    Repair any identified wiring faults, replace the dosing injector if coil resistance is out of spec, or replace the DCU if the fault traces to the module output driver
  7. 7
    After repair, clear codes, perform an SCR system active test

Vehicles where we've handled P2049

Platforms in our catalogue with confirmed P2049 coverage.

AUDI A4 20D
VW TRANSPORTER
AUDI A6
2015
AUDI A7 30D
AUDI A6 30D
2015
AUDI A7

Related powertrain codes

Frequently asked questions

Can I drive with P2049 active?

Short term driving is possible but not recommended. The SCR system will not dose correctly. If the fault persists, many vehicles apply a progressive torque derate after a set number of drive cycles.

Is P2049 the same as the AdBlue injector being clogged?

No. P2049 is an electrical circuit fault (voltage too high on the control circuit), not a flow or blockage fault.

Could DEF fluid cause this code?

Yes indirectly. DEF is mildly corrosive and can crystallise in the injector connector if there is a small leak at the injector tip.

Does P2049 always mean the injector needs replacement?

Not necessarily. The fault is as likely to be in the wiring harness or connector as in the injector itself.

Disabling P2049 in software

RaceTune can permanently disable P2049 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

ECUs with a P2049 disable in our catalogue

Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.

  • Bosch EDC17C60 verified 2 software versions
  • Bosch EDC17C74 verified 2 software versions
  • Bosch EDC17CP44 verified 1 software version
  • Bosch MD1CP004 verified 1 software version

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

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