P2742Transmission
Transmission Fluid Temperature Sensor B Circuit Low
P2742 means the transmission fluid temperature sensor B circuit signal is lower than expected, often from a short or a failed sensor.
🚗 Drivable short term but get it checked. A low signal misreports fluid temperature.
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🎯 Top Causes, Ranked by Likelihood
#1Short to ground in wiring$100-$350
A short pulls the signal low.
#2Faulty sensor B$100-$350
An internally shorted sensor reads low.
#3Corroded connector$80-$250
Corrosion causes a low reading.
#4TCM fault$500-$1200
The reading circuit has failed low.
🩺 Common Symptoms
- Check engine light
- Harsh or erratic shifts
- Incorrect temperature reading
- Lockup issues
💰 Repair Cost: DIY vs Shop
📋 Free OBD2 Code Cheat Sheet
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🔧 How to Diagnose P2742
1Scan live data for an implausibly low temperature
2Inspect wiring for shorts to ground
3Test sensor resistance
4Replace the sensor if shorted
❓ Frequently Asked Questions
Can I drive with P2742?
Yes briefly, but shift timing may be affected, so get it diagnosed.
What does circuit low mean?
The signal voltage is lower than the sensor should ever produce, indicating a short.
How much to fix P2742?
Usually $150-$500 including a sensor and labor.
🔗 Related Codes
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