P1742 — Auto Trans Diagnosis Input Signal Malfunction

What Does P1742 Mean?

P1742 is a manufacturer-specific diagnostic trouble code: Auto Trans Diagnosis Input Signal Malfunction. This code applies to SUBARU, OTHER, MAZDA, FORD, LINCOLN 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 P1742

⚠️ Check Engine Light (MIL) illuminated
⚠️ Auto Trans Diagnosis Input Signal not operating correctly
⚠️ Related system in reduced functionality mode
⚠️ Reduced engine performance

Common Causes

🔍 Auto Trans Diagnosis Input Signal has failed or is degraded
🔍 Wiring or connector issue in Auto Trans Diagnosis Input Signal circuit
🔍 Related mechanical component affecting Auto Trans Diagnosis Input Signal
🔍 Software update needed for ECM/PCM

Frequently Asked Questions

What does P1742 mean?

P1742 indicates: Auto Trans Diagnosis Input Signal Malfunction. The vehicle's computer has detected that the Auto Trans Diagnosis Input Signal is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P1742?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P1742 for extended periods may cause additional problems.

How much does it cost to fix P1742?

Repair costs for P1742 typically range from $80 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 Auto Trans Diagnosis Input Signal and related wiring
🔧 Replace faulty Auto Trans Diagnosis Input Signal

1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
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.

P1742: Auto Trans Diagnosis Input Signal Malfunction