P045C

EGR B Control Circuit Low

Q: Is it safe to drive with P045C?

Short-term yes, but a malfunctioning EGR can cause pinging under load, so have it repaired before long or heavy driving.

Q: Can I just clear P045C?

It will come back on the next drive cycle unless the wiring, solenoid, or valve fault is actually fixed.

Exhaust gas recirculation (EGR) Generic OBD-II Medium

What it means

P045C means the ECM has seen an abnormally low voltage on the control circuit for the "B" EGR valve — typically a short to ground or an open in the wiring or solenoid. It's an emissions-system fault: the engine still starts and drives, but the EGR valve may not move as commanded, which can cause pinging or rough running under load.

Medium

Can I keep driving? Usually drivable — the engine runs, but you may notice a check-engine light and rough running or pinging under load until repaired.

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
Pinging or knocking under load
Rough idle or slight hesitation
Often no obvious drivability change

Common causes

Most likely first

Short to ground or open in the EGR 'B' control circuit wiringLikely
Failed EGR control solenoid or actuatorCommon
Loose or corroded connector at the EGR valveCommon
Carbon buildup binding the EGR valveLess often
Rarely, a failed ECM driverLess often

How to diagnose & fix

Work through it in order

Inspect the EGR 'B' valve connector and wiring for damage, shorts to ground, or corrosion.
Measure the control circuit resistance and check for a low/grounded signal against spec.
Test the EGR solenoid/actuator; replace it if the winding is out of range.
Clean carbon from the EGR valve and passages, then clear the code and re-test.

FAQ

Quick answers

Is it safe to drive with P045C?+

Short-term yes, but a malfunctioning EGR can cause pinging under load, so have it repaired before long or heavy driving.

Can I just clear P045C?+

It will come back on the next drive cycle unless the wiring, solenoid, or valve fault is actually fixed.

Read & clear P045C 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