Missing engine speed signal with engine off?

Name: Missing engine speed signal with engine off?
Uploaded: 2026-04-06
Duration: 1 min 10 s
Channel: Paulo
Description: Learn why GM S10 and Blazer 2.2 EFI flash code 12 is normal with the engine off and does not mean a bad crankshaft sensor.

2026-04-06 · 1:10 · 1,253 views

Video by Paulo — Paulo's Garage.

🎙️ Video audio is in Portuguese. Localized technical summary, torque specs, and procedures below.

Correction of a misunderstanding about code 12 on S10/Blazer fault codes: it always appears with the engine off because there is no RPM signal. The video serves as an educational complement to reading flash codes via the check engine light.