What Does P1303 Mean?
The PCM has detected that the Exhaust Gas Recirculation (EGR) system calibration values are incorrect or corrupted. This indicates a software or memory issue within the PCM related to EGR control parameters.
Common Causes
40%
Corrupted PCM memory or calibration data
30%
Incomplete or failed PCM software update/reflash
15%
Low battery voltage during PCM programming causing corruption
10%
Failed PCM requiring replacement and programming
5%
Incorrect PCM installed for vehicle application
Diagnostic Steps
1
Step 1: Check for any available PCM software updates or technical service bulletins (TSBs) related to EGR calibration
2
Step 2: Test battery and charging system to ensure proper voltage before attempting PCM reflash
3
Step 3: Attempt to clear code and perform PCM relearn procedure according to manufacturer specifications
4
Step 4: Verify PCM part number matches vehicle application and build date
5
Step 5: If code returns, perform complete PCM reprogramming with latest calibration files using factory scan tool
Estimated Repair Cost
$150 - $1,200
Parts + labor, varies by vehicle and location
The PCM has detected that the Exhaust Gas Recirculation (EGR) system calibration values are incorrect or corrupted. This indicates a software or memory issue within the PCM related to EGR control parameters.
The most common cause of P1303 (EGR Calibration Fault) is: Corrupted PCM memory or calibration data
Typical repair costs for P1303 range from $150 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is generally safe to drive but emissions will be affected. May experience poor fuel economy or slight performance issues. Check engine light will remain on.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1303 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control System / EGR System
Difficulty
Type
Manufacturer
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