What Does P1420 Mean?
The Powertrain Control Module has detected an electrical malfunction within the Secondary Air Injection control module circuit. This indicates a communication or power supply issue with the SAI control unit.
Common Causes
40%
Failed SAI control module or internal relay failure
25%
Blown fuse or open circuit in SAI control module power supply
20%
Corroded or damaged control module connector pins
15%
Ground circuit fault or poor ground connection
Diagnostic Steps
1
Step 1: Check all fuses related to the SAI system using fuse diagram - test both power in and out of fuse
2
Step 2: Inspect SAI control module connector for corrosion, bent pins, or water intrusion
3
Step 3: Using wiring diagram, test for battery voltage at control module power supply pin with key on
4
Step 4: Verify good ground at control module ground circuit using voltage drop test (should be less than 0.1V)
5
Step 5: If power and ground are good, test control module operation with scan tool active tests, replace module if non-responsive
Estimated Repair Cost
$200 - $700
Parts + labor, varies by vehicle and location
The Powertrain Control Module has detected an electrical malfunction within the Secondary Air Injection control module circuit. This indicates a communication or power supply issue with the SAI control unit.
The most common cause of P1420 (Secondary Air Injection Control Module Electrical Malfunction) is: Failed SAI control module or internal relay failure
Typical repair costs for P1420 range from $200 to $700, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive with no immediate safety concerns. This affects only cold-start emissions performance and may cause failed emissions testing.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1420 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control - Secondary Air Injection
Difficulty
Type
Manufacturer
Recommended Tools
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