What Does P1433 Mean?
The powertrain control module has detected an open circuit in the secondary air injection pump relay control circuit. This means electrical continuity is broken between the PCM and the relay, preventing the secondary air system from operating during cold start emissions reduction.
Common Causes
35%
Open or broken wiring in relay control circuit
30%
Failed secondary air pump relay
20%
Corroded or loose connector at relay or PCM
10%
Blown fuse in relay control circuit
5%
Failed PCM relay driver circuit
Diagnostic Steps
1
Step 1: Visually inspect relay, fuse, and all connectors for damage or corrosion
2
Step 2: Check fuse continuity with multimeter
3
Step 3: Test relay by swapping with known good relay of same type
4
Step 4: Backprobe relay control circuit wire and command relay on with scan tool while checking for battery voltage at relay coil
5
Step 5: Check wiring continuity between PCM and relay connector using wiring diagram
Estimated Repair Cost
$75 - $300
Parts + labor, varies by vehicle and location
The powertrain control module has detected an open circuit in the secondary air injection pump relay control circuit. This means electrical continuity is broken between the PCM and the relay, preventing the secondary air system from operating during cold start emissions reduction.
The most common cause of P1433 (Secondary Air Injection Pump Relay Circuit Open) is: Open or broken wiring in relay control circuit
Typical repair costs for P1433 range from $75 to $300, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is safe to drive. Emissions may be slightly elevated during cold starts and check engine light will remain illuminated.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1433 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control System
Difficulty
Type
Manufacturer
Recommended Tools
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