P050B

Cold Start Ignition Timing Performance

Q: Is it safe to drive with P050B?

Short trips are usually okay, but the engine may knock when cold, and sustained knock can cause damage over time. Have it diagnosed rather than ignoring it.

Q: Can I just clear P050B?

It will return on the next cold start until the underlying cause — often a weak battery or a crank/cam sensor — is repaired.

Ignition timing Generic OBD-II High

What it means

P050B means the ECM found that ignition timing during a cold start didn't meet its target. Cold-start timing is tightly controlled to light off the catalyst and run smoothly before the engine warms up. Common causes include a weak battery, a failing crank or cam sensor, or VVT that isn't responding. The engine usually still starts, but cold knock and rough running should be diagnosed to avoid engine wear.

High

Can I keep driving? Usually yes — the engine starts and runs, but you may get knock and rough running when cold. Sustained knock can damage the engine, so don't put off the repair.

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
Engine knock or ping on acceleration when cold
Intermittent stumble or miss during warm-up
Poor fuel economy

Common causes

Most likely first

Weak or low battery slowing cranking and affecting cold-start timingLikely
Faulty crankshaft or camshaft position sensorCommon
Damaged wiring or poor connection at the crank/cam sensorCommon
Variable valve timing actuator or solenoid not responding on cold startLess often
ECM fault (rare)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data to confirm the fault sets during cold starts.
Test the battery and charging system; a weak battery is a common, cheap cause.
Inspect the crankshaft and camshaft sensor wiring and connectors for damage or corrosion.
Check the crank/cam sensor signals and VVT operation with a scan tool.
Repair wiring or replace the faulty sensor, then clear and re-test on a cold start.

FAQ

Quick answers

Is it safe to drive with P050B?+

Short trips are usually okay, but the engine may knock when cold, and sustained knock can cause damage over time. Have it diagnosed rather than ignoring it.

Can I just clear P050B?+

It will return on the next cold start until the underlying cause — often a weak battery or a crank/cam sensor — is repaired.

Read & clear P050B 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