What Does P044C Mean?
The EGR sensor 'C' is reporting a signal voltage that is below the normal operating range. This typically indicates an open circuit, a grounded signal wire, or a failed sensor pulling the voltage low. The PCM will likely disable EGR operation, causing increased NOx emissions. The driver will see a check engine light.
Common Causes
35%
Failed EGR sensor 'C' with internally shorted or grounded element
30%
Signal wire shorted to ground in the wiring harness
15%
Corroded connector causing voltage drop on signal wire
15%
Open 5V reference supply wire (signal defaults low)
5%
PCM input pull-up circuit failure
Diagnostic Steps
1
Check the EGR sensor 'C' signal voltage on live data. A low circuit code typically means the signal is below 0.2-0.3V. Note the exact reading.
2
Disconnect the EGR sensor connector. If the voltage jumps to approximately 5V (or reference voltage) at the PCM, the sensor is shorted internally and needs replacement.
3
If voltage stays low with the sensor disconnected, check the signal wire for a short to ground: measure resistance from the signal pin to chassis ground at the harness connector. Should read OL.
4
Verify the 5V reference voltage is present at the harness connector. If missing, trace the 5V reference circuit back to the PCM checking for opens or shorts (this reference may be shared with other sensors).
5
Inspect the connector for moisture intrusion, corrosion, or terminal damage that could create a low-resistance path to ground.
Estimated Repair Cost
$100 - $400
Parts + labor, varies by vehicle and location
The EGR sensor 'C' is reporting a signal voltage that is below the normal operating range. This typically indicates an open circuit, a grounded signal wire, or a failed sensor pulling the voltage low. The PCM will likely disable EGR operation, causing increased NOx emissions. The driver will see a c...
The most common cause of P044C (Exhaust Gas Recirculation Sensor "C" Circuit Low) is: Failed EGR sensor 'C' with internally shorted or grounded element
Typical repair costs for P044C range from $100 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive for short distances. The PCM will default to no EGR operation, which increases NOx emissions but does not pose an immediate safety risk. Avoid extended high-load driving as combustion temperatures may be elevated.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P044C to identify the root cause.
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Quick Info
Category
Powertrain
System
EGR / Emissions System
Difficulty
Type
Generic (SAE)
Recommended Tools
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