P2049

Code

Generic P — Powertrain

Reductant Injection Valve Circuit High Bank 1 Unit 1

Brand: Generic

Type: P — Powertrain

Views: UK: 20 EN: 32 RU: 42

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Open or damaged wiring in reductant injector control circuit (broken conductor, chafing)
Short to battery (B+) on the injector control lead
Corroded or loose connector at the reductant injection valve
Failed reductant injection valve (internal short or open)
Blown or corroded fuse or faulty relay powering the injector circuit
Poor ground at valve or ECM/PCM

Read freeze frame and live data with a scan tool (reductant injector status, commanded duty, system voltage)
Visually inspect injector connector, wiring harness along frame and engine for damage or rubbing
Inspect fuses and relays related to reductant injection and replace if suspect
Back-probe injector connector and measure voltage with key ON and while commanding injector ON/OFF
Measure injector coil resistance with connector disconnected
Perform wiggle test on harness while monitoring live data for intermittent faults

Resting control line voltage with valve disconnected: near battery voltage if circuit is pulled-up, or within expected reference range for vehicle
Commanded duty cycle or ON/OFF state as shown by scan tool (0–100% for pulse-width controlled valves)
Injector coil resistance (typical solenoid valves commonly 2–30 ohms; consult vehicle spec)
Injector current when commanded ON (often 0–2 A depending on valve design)
Short-to-battery condition: control line reads battery voltage regardless of commanded state

Retrieve full freeze frame data and any related DTCs. Note battery voltage and system state when code set.
Visually inspect reductant injector connector, harness, and nearby wiring for damage, corrosion, or fluid contamination. Repair obvious issues.
With IGN ON (engine OFF) and connector connected, back-probe the injector control wire and monitor voltage. Command injector ON via scan tool and observe changes. A 'high' fault usually shows battery voltage at the control line regardless of command.
Disconnect the injector connector and measure resistance of the injector coil to ground with a multimeter. Compare to manufacturer spec. An open or shorted coil indicates a failed valve.
Check for short-to-B+ by measuring continuity between control wire and battery positive with harness disconnected. No continuity should exist. If continuity present, locate and repair short.
Inspect and test associated fuses and relays. Replace as required.
Check ground points for good connection and low resistance. Repair any poor grounds.
If wiring and valve tests good, test the ECM/PCM driver output. If driver is suspected failed, verify with a known-good module or follow manufacturer procedures before replacement.
Clear codes, perform a functional test of reductant dosing, and verify code does not return under the same conditions.