P1819
Internal mode switch no start wrong range
What it means
P1819. Internal mode switch no start wrong range. Gear selector signals make no valid combination. This Chevy-enhanced code applies to Silverado, Sierra, Tahoe, Suburban with 4L60E 1999 to 2006. Impala with 4T65E..
Findings, check these first
- Faulty internal mode switch
- Misadjusted shift linkage
- Water in transmission connector
- Worn manual valve linkage
- Damaged wiring to switch
Standard procedure
- Check shift linkage adjustment
- Inspect transmission connector for fluid
- Test mode switch positions on scan tool
- Repair linkage or seal leak
- Replace internal mode switch if signals wrong
Look up another code
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Sources and review
Review: checked against the recorded source material.
- P1819 CHEVROLET Internal Mode Switch
archived reference page (autocodes.com via Wayback Machine)
Supports: code identity and Chevrolet application
Fetched directly. The Chevrolet page describes an invalid combination of internal mode switch signals, matching the catalog. Model and year fitment remain curator claims.
Last updated 2026-09-25.
Report a correction for P1819. Include your vehicle, the issue and a source if you have one.