P2053: Reductant Injection Valve Circuit/Open (Bank 1 Unit 2)

P2053 concerns a second DEF injector on the same exhaust line as Bank 1, unit 1, used where a manufacturer doses at two points, for instance ahead of two separate catalysts. GM's 2025 table (25OBDG04B, which also covers an inline-six diesel) monitors this DEF metering valve 2 with the same open-load logic as valve 1: more than 11 V, 30 faulty samples out of 60 at 100 ms, Type A; a separate P1C30 checks its coil temperature after a long soak. Deutz's EMR5 engines assign P2053 to metering unit 2, with failure bytes for current above normal (grounded) and below normal (open). If valve 2 drops out, valve 1 keeps working, so the downstream catalyst simply loses its DEF and NOx rises only partly, often noticed just through the MIL.

Medium severity. Can I keep driving?Deal with it soon. If the instrument cluster shows a countdown, the car may not restart once it reaches zero.

Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank.

Symptoms

MIL on
Slightly higher NOx, little noticeable otherwise
DEF system message

Most likely causes

Disconnected or corroded plug at DEF injector 2
Broken wire between control module and injector 2
Open coil in injector 2

What to check, in order

Start with the simplest. You can tick off each step.

Check the AdBlue/DEF level and quality, and do not add additives or water
Check the continuity of the wire between the component and the control module.
Look for white crystals around the injector and the tank
Check connectors and heaters with the scanner
Run the dosing test available on your diagnostic tool
Replace parts only when the test points to that component

Good to know

Repair difficulty: medium
It can trigger limp mode.
It affects emissions.

What each character of P2053 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
0: Subsystem depends on the code range
53: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2053?

Deal with it soon. If the instrument cluster shows a countdown, the car may not restart once it reaches zero.

What causes code P2053?

The most common causes are: disconnected or corroded plug at DEF injector 2; broken wire between control module and injector 2; open coil in injector 2.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.