Chevrolet P1336: Crank Variation Not Learned — Fix
On Chevrolet vehicles, P1336 means the crankshaft position system variation (CASE) relearn has not been performed — needed so the ECM can accurately detect misfires.
- Applies to
- Chevrolet vehicles
- Est. repair cost
- $80 – $600
- Time to fix
- 30 minutes – 2 hours
What it means
Causes are usually that a required relearn procedure was not done after a repair/reflash; sometimes a crank sensor or reluctor fault. P1xxx codes are manufacturer-specific — P1336 is defined by Chevrolet (not part of the generic SAE J2012 set), so this definition applies to Chevrolet vehicles. Model years can vary, so confirm against the Chevrolet service manual. Fix the fault, then clear the code with a scan tool.
Symptoms
- Check engine light on
- May be paired with misfire codes
- Usually little direct drivability effect
How to fix it
- 1
Perform the CASE relearn
1. Use a scan tool to run the crankshaft variation (CASE) relearn procedure.
- 2
Check the crank sensor
1. If the relearn fails, inspect the crank sensor and reluctor ring. 2. Repair, then relearn and clear the code.
Frequently asked questions
Why do I need a relearn for P1336?
After certain repairs or a reflash, the ECM must relearn the crank signal variation to detect misfires accurately. A scan tool runs the procedure.
Last updated July 19, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.