What Does P2259 Mean?
The PCM has detected a low voltage condition on the Secondary Air Injection system control circuit B. Circuit voltage is below the minimum specification needed to properly activate the secondary air system components.
Common Causes
30%
Shorted to ground in AIR solenoid valve B control circuit wiring
25%
Failed secondary air bypass/switching valve B with internal short
20%
Damaged AIR valve connector or corroded terminals
15%
Failed AIR system relay for circuit B
10%
PCM driver circuit failure for circuit B
Diagnostic Steps
1
Step 1: Disconnect secondary air valve B and check control circuit for short to ground with DVOM
2
Step 2: Inspect AIR valve B connector and terminals for damage, moisture, or corrosion
3
Step 3: Test AIR solenoid valve B resistance (typically 20-50 ohms depending on design)
4
Step 4: Command AIR valve B on with scan tool and verify voltage at valve connector
5
Step 5: Replace AIR valve B if control circuit and power supply test normal
Estimated Repair Cost
$150 - $550
Parts + labor, varies by vehicle and location
The PCM has detected a low voltage condition on the Secondary Air Injection system control circuit B. Circuit voltage is below the minimum specification needed to properly activate the secondary air system components.
The most common cause of P2259 (Secondary Air Injection System Control "B" Circuit Low) is: Shorted to ground in AIR solenoid valve B control circuit wiring
Typical repair costs for P2259 range from $150 to $550, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive without restriction. AIR system failure only impacts emissions during engine warm-up cycle.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2259 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
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