Cruise Control Throttle Response Fast
The C0421 code means the vehicle's onboard diagnostic system has detected: Cruise Control Throttle Response Fast. This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $80 - $350 (parts and labor)
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Common Symptoms
- Cruise control inoperative
- Speed surges during cruise
- Vehicle decelerates on hills with cruise on
- Cruise control warning indicator on
Probable Causes (Ranked by Likelihood)
- Faulty vehicle speed sensor signal Very High
- Cruise control vacuum leak High
- Failed throttle actuator Moderate
- Transmission input signal error Low
Step-by-Step Diagnostic Procedure
-
Monitor vehicle speed signal on scan tool
-
Check throttle actuator response
-
Inspect vacuum hoses for leaks
-
Test brake and clutch switch inputs
Frequently Asked Questions
What does code C0421 mean?
C0421 indicates a fault with the cruise control throttle response fast.
Can I drive with C0421?
You can drive safely, but the affected feature will be unavailable until repaired.
How much does it cost to fix C0421?
Typical repair costs are $80 - $350 (parts and labor).
Sources
This page is built from documented references. Verify against your own service info before repair work.
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