P2742 — Transmission Fluid Temperature Sensor B Circuit Low

What Does P2742 Mean?

P2742 is a diagnostic trouble code indicating: Transmission Fluid Temperature Sensor B Circuit Low. This code relates to the powertrain system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P2742

⚠️ Check Engine Light (MIL) illuminated
⚠️ Transmission Fluid Temperature Sensor B reading at zero or minimum value
⚠️ Related system not functioning or in fail-safe mode
⚠️ Reduced engine performance

Common Causes

🔍 Open or broken wire in Transmission Fluid Temperature Sensor B circuit
🔍 Poor ground connection at Transmission Fluid Temperature Sensor B
🔍 Faulty Transmission Fluid Temperature Sensor B with no output signal
🔍 Disconnected or loose Transmission Fluid Temperature Sensor B connector
🔍 Blown fuse in related circuit

Frequently Asked Questions

What does P2742 mean?

P2742 indicates: Transmission Fluid Temperature Sensor B Circuit Low. The vehicle's computer has detected that the Transmission Fluid Temperature Sensor B is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P2742?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P2742 for extended periods may cause additional problems.

How much does it cost to fix P2742?

Repair costs for P2742 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

🔧 Repair broken wire or restore ground in Transmission Fluid Temperature Sensor B circuit
🔧 Clean and secure Transmission Fluid Temperature Sensor B connector and ground points
🔧 Replace failed Transmission Fluid Temperature Sensor B

1
Find your vehicle above
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2
Check for recalls
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3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

P2742: Transmission Fluid Temperature Sensor B Circuit Low