P1418: Secondary Air Injection System Relay A Control Circuit High

BUICK CADILLAC CHEVY CHRYSLER GM GMC OLDSMOBILE PLYMOUTH

Severity

Medium

System

Manufacturer-Specific Powertrain

Last reviewed: Jan 1, 0001 Last updated: Jan 1, 0001

Methodology: We combine code standards with complaint and reliability patterns, then review for clear, vehicle-first diagnosis steps.

Sources: SAE/OBD-II definitions, manufacturer service information, and public reliability reports (including NHTSA where applicable).

Limits: Guidance is informational and may not match every model-year or revision. Confirm with the official manual and diagnostics before replacing parts. For safety-critical or electrical work, use a qualified technician.

What Does P1418 Mean?

P1418 is a manufacturer-specific diagnostic trouble code: Secondary Air Injection System Relay A Control Circuit High. This code applies to BUICK, CADILLAC, CHEVY, CHRYSLER, GM vehicles. Unlike generic OBD-II codes, manufacturer-specific codes are defined by the vehicle maker and may only apply to certain makes and models.

Symptoms of P1418

⚠️ Check Engine Light (MIL) illuminated
⚠️ Secondary Air Injection System Relay A reading stuck at maximum value
⚠️ Related system operating erratically or in default mode
⚠️ Reduced engine performance

Common Causes

🔍 Short to voltage in Secondary Air Injection System Relay A wiring harness
🔍 Corroded or water-damaged Secondary Air Injection System Relay A connector
🔍 Faulty Secondary Air Injection System Relay A outputting maximum voltage
🔍 Damaged wiring rubbing against metal components
🔍 ECM/PCM internal fault (rare)

Frequently Asked Questions

What does P1418 mean?

P1418 indicates: Secondary Air Injection System Relay A Control Circuit High. The vehicle's computer has detected that the Secondary Air Injection System Relay A is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P1418?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P1418 for extended periods may cause additional problems.

How much does it cost to fix P1418?

Repair costs for P1418 typically range from $20 to $300, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.

What To Do Next

Possible Fixes

🔧 Inspect and repair Secondary Air Injection System Relay A wiring for short to voltage
🔧 Clean or replace corroded Secondary Air Injection System Relay A connector
🔧 Replace faulty Secondary Air Injection System Relay A

1
Find your vehicle above
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2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.