OBD Code P0570: Cruise Control Coast Signal Malfunction

Q: What does OBD code P0570 mean?

Cruise Control Coast Signal Malfunction. Your cruise control's coast function isn't working properly—it's like a dimmer switch that won't send the right signal to turn down your engine speed. The ECU can't tell when you want to coast, so it can't execute that command.

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What This Actually Means

In plain language — no jargon

Your cruise control's coast function isn't working properly—it's like a dimmer switch that won't send the right signal to turn down your engine speed. The ECU can't tell when you want to coast, so it can't execute that command.

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Symptoms You May Notice

3 known symptoms for this code

Cruise control coast function doesn't work or behaves erratically

Check Engine Light (CEL) illuminated

Cruise control may not engage or disengage properly

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Embedded Systems Insight

What the ECU/ECM is actually computing

The ECM monitors the coast control switch signal voltage and logic state from the cruise control stalk. It expects a clean digital or analog signal transition when the driver activates the coast feature. If the signal is missing, intermittent, or out of range, the ECU logs a fault.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Coast switch signal voltage	0V or 5V (clean digital transition)	Floating voltage, stuck state, or no signal detected
Signal continuity/duration	Proper pulse or hold duration	Intermittent dropout or timeout error

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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex

1

Cruise control stalk connector

Disconnect and reconnect the cruise control stalk electrical connector to reseat any loose pins.

2

Cruise control switch contacts

Clean the coast switch contacts with electrical contact cleaner to remove corrosion or debris.

3

Cruise control stalk assembly

Replace the entire stalk if internal switch contacts are worn or damaged beyond cleaning.