What Does P0577 Mean?
The ECM has detected that the cruise control input circuit is reading above the maximum acceptable voltage threshold. This high-voltage condition typically indicates an open circuit in the cruise control switch network, a disconnected switch, or a signal wire that has lost its ground reference and is floating to the reference voltage level.
Common Causes
35%
Open circuit in the cruise control switch wiring due to a broken wire, disconnected connector, or failed clock spring
30%
Cruise control switch assembly with open internal circuit or broken trace in the resistive-ladder network
25%
Disconnected cruise control switch connector at the steering column base or clock spring interface
10%
ECM internal pull-up resistor on the cruise input circuit reading high due to no external load from the switch network
Diagnostic Steps
1
Step 1: Measure the cruise control input voltage at the ECM connector. A reading near 5V or battery voltage with no buttons pressed indicates an open circuit between the ECM and the switch network.
2
Step 2: Check all cruise control connectors for proper engagement, starting at the clock spring connector on the steering column. A disconnected connector is the most common simple cause.
3
Step 3: If connectors are seated, measure continuity from the ECM cruise input pin back to the switch connector. An open circuit confirms a broken wire or failed clock spring trace.
4
Step 4: Test the clock spring by measuring continuity on the cruise control circuit while rotating the steering wheel slowly. An intermittent open indicates a fractured trace inside the clock spring.
5
Step 5: If the wiring and clock spring are intact, test the switch assembly. Apply the expected ground or resistance load at the ECM connector to verify the ECM responds to a valid cruise input. Replace the switch if it has an open internal circuit.
Estimated Repair Cost
$30 - $400
Parts + labor, varies by vehicle and location
The ECM has detected that the cruise control input circuit is reading above the maximum acceptable voltage threshold. This high-voltage condition typically indicates an open circuit in the cruise control switch network, a disconnected switch, or a signal wire that has lost its ground reference and i...
The most common cause of P0577 (Cruise Control Input Circuit High) is: Open circuit in the cruise control switch wiring due to a broken wire, disconnected connector, or failed clock spring
Typical repair costs for P0577 range from $30 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A high-input cruise control circuit renders cruise control completely inoperative. No safety hazard exists because cruise cannot engage and all other vehicle functions remain normal.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0577 to identify the root cause.
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Quick Info
Category
Powertrain
System
Cruise Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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