P2048

Reductant Injection Valve Circuit Low Bank 1 Unit 1

Q: Is it safe to drive with P2048?

Briefly, yes, but SCR/DEF faults usually force a power derate and can prevent restart after enough drive cycles, so fix it soon.

Q: Can I just clear P2048?

It returns until the injector or its circuit is repaired; clearing won't stop the derate.

Diesel exhaust / SCR emissions Generic OBD-II Medium

What it means

P2048 means the PCM detected low voltage (a short-to-ground or open) on the reductant injection valve circuit for bank 1, unit 1 — the DEF injector on a diesel SCR system. This injector meters diesel exhaust fluid into the exhaust to reduce NOx. The fault mainly affects emissions, but diesels often respond with warnings and a power derate. The engine still starts and runs.

Medium

Can I keep driving? Drivable at first, but diesel SCR faults often trigger a power derate and eventual no-restart; repair promptly.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
SCR / emissions or DEF warning message
Reduced engine power (derate) if the fault persists
Higher tailpipe NOx / failed emissions test

Common causes

Most likely first

Reductant injection valve (DEF injector) circuit shorted to ground or openLikely
Damaged wiring or corroded connector at the injectorCommon
Failed reductant injection valveCommon
Poor ground or power feed to the injector circuitLess often
Faulty DEF control module / PCM (rare)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and inspect the injector wiring and connector for a short-to-ground or open.
Measure the injector's resistance and the circuit voltage against spec.
Repair any damaged wiring, poor ground, or corroded connector.
Replace the reductant injection valve if it tests out of range.
Clear the code and re-test; consider the control module only after the circuit checks out.

FAQ

Quick answers

Is it safe to drive with P2048?+

Briefly, yes, but SCR/DEF faults usually force a power derate and can prevent restart after enough drive cycles, so fix it soon.

Can I just clear P2048?+

It returns until the injector or its circuit is repaired; clearing won't stop the derate.

Read & clear P2048 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX