Cruise Control System - Processor Malfunction
The P0593 code means the vehicle's onboard diagnostic system has detected: Cruise Control System - Processor Malfunction. This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $50 - $400 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Cruise control processor not responding
- Cruise control system inoperative
- No response from cruise control buttons
Probable Causes (Ranked by Likelihood)
- Failed cruise control module or processor Very High
- Wiring damage or corrosion in the circuit High
- Poor connector contact or backed-out pins Moderate
- ECM or control module circuit failure Low
Frequently Asked Questions
What does P0593 mean?
P0593 indicates a malfunction in the cruise control system - processor malfunction. This prevents the cruise control system from operating correctly.
Can I still drive with this cruise control code?
Yes. Cruise control codes do not affect normal vehicle operation. The vehicle drives normally; only the cruise control convenience feature is affected.
Should I fix a cruise control code right away?
Cruise control codes are low priority for drivability and safety. However, the Check Engine Light may mask other more serious codes. Consider diagnosis when convenient.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Use a scan tool to read Cruise Control System related data
-
Inspect all related wiring and connectors for damage, corrosion, or loose connections
-
Measure circuit voltage and resistance to identify opens, shorts, or high resistance
-
Command the affected component with a scan tool to verify it responds to ECM commands
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- 2008-2018 Ford F-150
- 2010-2020 Toyota Camry
- 2009-2019 Honda Accord
- 2011-2020 Chevrolet Silverado
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