What Does P1505 Mean?
An electrical fault has been detected in the idle speed control valve closing solenoid control circuit. This indicates a short circuit, resistance issue, or other electrical abnormality preventing proper closing solenoid operation.
Common Causes
35%
Short to ground or short to power in closing solenoid wiring
30%
Partially shorted or high resistance in closing solenoid coil
20%
Water intrusion or corrosion causing intermittent short in connector
15%
Chafed wiring harness causing intermittent short to chassis ground
Diagnostic Steps
1
Step 1: Disconnect ISC valve connector and inspect for moisture, corrosion, or pin damage
2
Step 2: Measure closing solenoid coil resistance with ISC valve disconnected (compare to specifications)
3
Step 3: Check for short to ground on control circuit wire from PCM side with ISC disconnected
4
Step 4: Check for short to power on control circuit with key off and ISC disconnected
5
Step 5: Inspect wiring harness routing for chafing points or damage near heat sources or sharp edges
Estimated Repair Cost
$100 - $500
Parts + labor, varies by vehicle and location
An electrical fault has been detected in the idle speed control valve closing solenoid control circuit. This indicates a short circuit, resistance issue, or other electrical abnormality preventing proper closing solenoid operation.
The most common cause of P1505 (Idle Speed Control Valve Closing Solenoid Control Circuit Electrial) is: Short to ground or short to power in closing solenoid wiring
Typical repair costs for P1505 range from $100 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Unstable idle speed may cause stalling at stops, creating potential safety hazard in traffic. High idle conditions may cause unexpected vehicle movement.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1505 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Idle Speed Control
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
