What are the common causes of P045B?

A failed EGR valve B or its motor. An EGR valve B stuck open or closed. An erratic EGR B control signal. A vacuum leak or intake leak near the EGR port. An ECM fault on the EGR B control.

Command EGR valve B through its range on a scan tool. Inspect valve B for carbon and sticking. Check the EGR B control wiring for damage. Smoke test the intake near the EGR port. Replace valve B if it does not track. Clear the code and retest.

P045B

EGR B Control Circuit Range/Performance

System: Auxiliary emission controls (P code)
Lamp: Check Engine Light
Category: Powertrain - Auxiliary Emissions Controls

What it means

P045B means EGR B Control Circuit Range/Performance.

Check these first

A failed EGR valve B or its motor
An EGR valve B stuck open or closed
An erratic EGR B control signal
A vacuum leak or intake leak near the EGR port
An ECM fault on the EGR B control

What to do next

Command EGR valve B through its range on a scan tool
Inspect valve B for carbon and sticking
Check the EGR B control wiring for damage
Smoke test the intake near the EGR port
Replace valve B if it does not track
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.