What Does P242C Mean?
The EGT sensor 3 on bank 1 is reporting voltage or temperature values that are consistently lower than the minimum threshold. This indicates the sensor circuit is reading abnormally cold temperatures.
Common Causes
40%
Shorted EGT sensor or internal sensor failure
35%
Short to ground in sensor wiring or harness
15%
Damaged or corroded sensor connector causing short
10%
ECM internal circuit fault
Diagnostic Steps
1
Step 1: Disconnect EGT sensor 3 connector and check for resistance between signal wire and ground
2
Step 2: Measure sensor internal resistance with connector unplugged
3
Step 3: Inspect wiring harness from sensor to ECM for chafing, pinching, or shorts to ground
4
Step 4: Check ECM connector terminals for corrosion or damage
5
Step 5: Replace sensor if internal resistance is out of specification or zero ohms
Estimated Repair Cost
$200 - $550
Parts + labor, varies by vehicle and location
The EGT sensor 3 on bank 1 is reporting voltage or temperature values that are consistently lower than the minimum threshold. This indicates the sensor circuit is reading abnormally cold temperatures.
The most common cause of P242C (Exhaust Gas Temperature Sensor Circuit Low Bank 1 Sensor 3) is: Shorted EGT sensor or internal sensor failure
Typical repair costs for P242C range from $200 to $550, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive short distances but may cause emission system damage if ignored. Vehicle may enter limp mode.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P242C to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control
Difficulty
Type
Generic (SAE)
Recommended Tools
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