What Does P1512 Mean?
The PCM has detected that the intake manifold changeover valve circuit is shorted to positive voltage (battery voltage). This means the circuit has an unintended connection to a power source, preventing proper valve control.
Common Causes
45%
Wiring harness chafing causing short to nearby power wire
30%
Failed IMRC solenoid with internal short to power
15%
Damaged connector with crossed or bent pins touching power circuit
10%
Aftermarket installation or previous repair causing improper wiring
Diagnostic Steps
1
Step 1: Disconnect IMRC valve connector and check if code clears (isolates valve from circuit)
2
Step 2: With connector disconnected, measure voltage on PCM side of harness (should be 0V with key on)
3
Step 3: Inspect wiring harness routing for contact with hot wires or heat sources
4
Step 4: Check for voltage at valve side with connector removed (should be 0V)
5
Step 5: Inspect connector terminals for damage, melting, or cross-contamination
Estimated Repair Cost
$150 - $550
Parts + labor, varies by vehicle and location
The PCM has detected that the intake manifold changeover valve circuit is shorted to positive voltage (battery voltage). This means the circuit has an unintended connection to a power source, preventing proper valve control.
The most common cause of P1512 (Intake Manifold Changeover Valve Circuit Short To Positive) is: Wiring harness chafing causing short to nearby power wire
Typical repair costs for P1512 range from $150 to $550, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive. Performance and fuel economy may be slightly reduced at certain engine speeds.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1512 to identify the root cause.
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Quick Info
Category
Powertrain
System
Variable Intake Manifold System
Difficulty
Type
Manufacturer
Recommended Tools
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