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

What it means

Reductant Injection Valve Circuit/Open (Bank 1 Unit 2): the circuit is open. This valve doses reductant (DEF/AdBlue) into the exhaust for SCR NOx reduction.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

The Bank 1 Unit 2 reductant injection valve meters DEF/AdBlue into the exhaust for SCR NOx reduction. P2053 sets when the control module detects an open electrical path in this specific valve circuit, preventing reliable injector operation.

Common causes

Most likely first.

1. Solenoid winding open
2. Pin pushed back out of connector body
3. Cracked solder joint inside the module or sensor

Symptoms

• Check engine light or NOx warning on
• AdBlue/DEF level or quality warning
• Possible no-start countdown after ignore period
• Failed emissions inspection (NOx)

How to diagnose it

1. Record freeze-frame data and check for related SCR dosing codes, then use a supported actuator test to confirm whether Bank 1 Unit 2 is commanded.
2. Inspect the Bank 1 Unit 2 injector connector for backed-out pins, corrosion, poor fit, or harness damage near the exhaust.
3. Test the valve winding for an open circuit according to the manufacturer's procedure and specification.
4. Check continuity through the Bank 1 Unit 2 control and supply wiring to the module, including terminal fit and intermittent opens when the harness is moved.
5. If the valve and wiring pass, diagnose the module driver circuit with the vehicle's service information.
6. After repair, repeat the supported dosing test and confirm the open-circuit code does not return.

Common fixes

• Secure the Bank 1 Unit 2 connector or repair a backed-out terminal.
• Repair an open or damaged wire in the Bank 1 Unit 2 valve circuit.
• Replace the Bank 1 Unit 2 injector if its winding is open.
• Repair a confirmed module driver fault and verify the injector command.

Can I keep driving?

If the vehicle behaves normally, limit driving and arrange repair soon because the Bank 1 Unit 2 injector may not dose reductant. Watch for SCR warnings or a countdown that could eventually prevent restarting.