P1587

Electronic Throttle Monitor Data Available

Powertrain Speed/Idle Control Electronic Throttle Control 🟡 Moderate — Fix within a week ⚠️ Drive with Care
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What This Actually Means

In plain language — no jargon

The engine computer has detected that throttle monitoring data is available but may not be functioning correctly—think of it like a security camera that's installed but not sending clear video to the monitor. This is typically an informational code indicating the electronic throttle control system needs attention.

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Symptoms You May Notice

3 known symptoms for this code
Check Engine Light illuminated
Reduced engine power or limp mode activation
Rough idle or hesitation during acceleration
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors the electronic throttle body's position sensor signals and compares actual throttle opening to commanded values. It checks for voltage consistency, signal rationality, and communication between the throttle control module and main ECU. When data is available but inconsistent or delayed, this code sets.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
Throttle Position Sensor Voltage 0.5-4.5V linear response Signal dropout, noise, or non-linear response
ECU-to-Throttle Module Communication Continuous sync within 50ms Communication delay or data mismatch detected
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
Throttle body connector
Disconnect and reconnect the throttle body electrical connector to reseat contacts and clear transient faults.
2
Engine air intake
Inspect intake hoses and connections for vacuum leaks that may affect throttle response signals.
3
Throttle body assembly
Clean throttle body with carburetor cleaner if carbon buildup is visible, as deposits can cause sensor reading errors.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code P1587 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.
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How to Clear Code P1587

What happens after you fix the fault

Once the fault is repaired, P1587 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.

The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.

✅ Safe to Clear When
  • Fault has been diagnosed and repaired
  • You want to confirm the repair worked
  • Code appeared after a sensor was cleaned
⚠️ Do Not Clear When
  • Preparing for an emissions/PUC test
  • Root cause is still undiagnosed
  • Check engine light is flashing
Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.