What Does P2184 Mean?
ECT sensor 2 is reporting voltage that is too low, indicating an implausibly high temperature reading (sensor resistance drops as temperature rises). This typically indicates a short to ground or failed sensor.
Common Causes
50%
ECT sensor 2 shorted internally or to ground
30%
Signal wire shorted to ground in harness
15%
Coolant contamination causing sensor failure
5%
PCM internal short circuit
Diagnostic Steps
1
Step 1: With ignition off, disconnect ECT sensor 2 and measure resistance; should read 2000-3000 ohms at room temperature (not near zero)
2
Step 2: Check voltage at sensor connector harness side with key on, engine off; should read approximately 5 volts reference voltage
3
Step 3: With sensor disconnected, check signal wire resistance to ground; should read infinite (open circuit)
4
Step 4: Inspect wiring harness for damage, pinching, or contact with hot engine components that could cause insulation failure
5
Step 5: If all circuits test normal, replace ECT sensor 2 and retest
Estimated Repair Cost
$80 - $350
Parts + labor, varies by vehicle and location
ECT sensor 2 is reporting voltage that is too low, indicating an implausibly high temperature reading (sensor resistance drops as temperature rises). This typically indicates a short to ground or failed sensor.
The most common cause of P2184 (Engine Coolant Temperature Sensor 2 Circuit Low) is: ECT sensor 2 shorted internally or to ground
Typical repair costs for P2184 range from $80 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive but PCM may default to substitute coolant temperature values, affecting fuel trim, idle quality, and emissions. Monitor temperature gauge for actual overheating.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2184 to identify the root cause.
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Quick Info
Category
Powertrain
System
Engine Cooling System
Difficulty
Type
Generic (SAE)
Recommended Tools
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