What does P1371 mean on a Chevy?

P1371. IC 4X Reference Circuit Too Few Pulses. Applies to Silverado, Sierra, Tahoe, Camaro, Corvette.

What causes P1371 on a Chevy?

Failing crankshaft position sensor dropping pulses Damaged 4X reluctor ring teeth Stretched timing chain altering pulse spacing Corroded CKP connector adding resistance Low starter cranking speed during capture

How do I fix P1371 on a Chevy?

Capture CKP 4X signal with a scope or Tech2 or GDS2 during cranking Inspect the reluctor ring through the sensor bore for damaged teeth Check CKP connector and harness for corrosion and chafing Verify cranking speed and battery health before condemning the sensor Replace the CKP sensor only on confirmed signal loss, then clear and verify pulse count

Code

P1371

IC 4X Reference Circuit Too Few Pulses

Category: Powertrain - Ignition
Severity: Check Engine Light
Applies to: Silverado, Sierra, Tahoe, Camaro, Corvette
Related: No single generic twin. See OBD Codes List

What it means

P1371. IC 4X Reference Circuit Too Few Pulses. This Chevy-enhanced code applies to Silverado, Sierra, Tahoe, Camaro, Corvette.

Findings, check these first

Failing crankshaft position sensor dropping pulses
Damaged 4X reluctor ring teeth
Stretched timing chain altering pulse spacing
Corroded CKP connector adding resistance
Low starter cranking speed during capture

Standard procedure

Capture CKP 4X signal with a scope or Tech2 or GDS2 during cranking
Inspect the reluctor ring through the sensor bore for damaged teeth
Check CKP connector and harness for corrosion and chafing
Verify cranking speed and battery health before condemning the sensor
Replace the CKP sensor only on confirmed signal loss, then clear and verify pulse count

Look up another code

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Sources and review

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Last updated 2026-09-13.

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