What Does P1585 Mean?
This code indicates the PCM has overridden the electronic throttle control system due to a detected malfunction. When the throttle monitor detects a condition that could cause unintended acceleration or loss of throttle control, the PCM takes authority over throttle position, typically commanding it to a safe idle or reduced power state. This is a critical safety intervention that requires prompt diagnosis.
Safety Warning
Vehicle will operate in a severely reduced power mode. This override exists to prevent unintended acceleration, which is a critical safety concern. Do not ignore this code or attempt to bypass the override.
Common Causes
30%
Electronic throttle body motor or position sensor failure
25%
Accelerator pedal position sensor fault or disagreement
20%
Wiring harness fault between throttle body and PCM
15%
Throttle body carbon buildup causing mechanical binding
10%
PCM internal fault requiring replacement or reflash
Diagnostic Steps
1
Retrieve all DTCs including pending codes—this code is usually accompanied by other ETC-related codes that point to the root cause.
2
Inspect the electronic throttle body for carbon buildup, smooth blade movement, and proper spring return action with the key off.
3
Monitor live data for commanded vs. actual throttle position; a large divergence confirms the override condition.
4
Check APP sensor voltages at idle and full sweep; verify they match expected voltage curves from the service manual.
5
Inspect all ETC wiring including the throttle body connector, APP sensor connector, and PCM harness connector for damage.
6
Clean or replace the throttle body as indicated, clear codes, and perform an ETC relearn procedure.
Estimated Repair Cost
$150 - $600
Parts + labor, varies by vehicle and location
This code indicates the PCM has overridden the electronic throttle control system due to a detected malfunction. When the throttle monitor detects a condition that could cause unintended acceleration or loss of throttle control, the PCM takes authority over throttle position, typically commanding it...
The most common cause of P1585 (Electronic Throttle Monitor PCM Override) is: Electronic throttle body motor or position sensor failure
Typical repair costs for P1585 range from $150 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle will operate in a severely reduced power mode. This override exists to prevent unintended acceleration, which is a critical safety concern. Do not ignore this code or attempt to bypass the override.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1585 to identify the root cause.
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Quick Info
Category
Powertrain
System
Electronic Throttle Control
Difficulty
Type
Manufacturer
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