P1399 Chevrolet Wheel Speed Sensor 2, G-Sensor Circuit Intermittent

Possible causes

– Valve clearance out of range
– Blocked EGR (exhaust gas recirculation) Passages

Tech description

Adjusting the valves will usually fix this problem.

What about the obd code?

The control module monitors the crankshaft speed and has detected a misfire condition

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Lack/loss of power
– Hard start
– Engine hesitation

P1399 Chevrolet Description

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, the Engine Control Module (ECM) can determine that a misfire is occurring.

– Valve clearance out of range