What Does P1506 Mean?
The PCM has detected a high voltage signal on the idle speed control valve opening solenoid control circuit. This indicates the control signal is stuck high or experiencing a short to voltage, preventing proper idle control valve operation.
Common Causes
40%
Short to battery voltage in opening solenoid control wiring
25%
Failed ISC valve with internal short to power in opening solenoid
20%
PCM driver circuit stuck high or failed in on-state
15%
Crossed wires or pinched harness causing short to power circuit
Diagnostic Steps
1
Step 1: Disconnect ISC valve connector and measure voltage on control wire from PCM with key on
2
Step 2: Check for battery voltage on control circuit wire with ISC disconnected (should be 0V with PCM commanding closed)
3
Step 3: Inspect wiring harness for damage or contact with power sources along entire routing
4
Step 4: Test PCM control circuit by monitoring voltage while commanding ISC valve open/closed with scan tool
5
Step 5: Verify proper ground circuit operation at ISC valve and PCM
Estimated Repair Cost
$120 - $550
Parts + labor, varies by vehicle and location
The PCM has detected a high voltage signal on the idle speed control valve opening solenoid control circuit. This indicates the control signal is stuck high or experiencing a short to voltage, preventing proper idle control valve operation.
The most common cause of P1506 (Idle Speed Control Valve Open Solenoid Control Circuit Signal High) is: Short to battery voltage in opening solenoid control wiring
Typical repair costs for P1506 range from $120 to $550, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Engine idle speed may be uncontrolled, potentially causing rough idle or stalling. High idle conditions may cause unexpected vehicle movement when shifting into gear.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1506 to identify the root cause.
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Quick Info
Category
Powertrain
System
Idle Speed Control
Difficulty
Type
Manufacturer
Recommended Tools
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