Applicable Systems
OBD-II
Symptoms
The APP sensor 2 signal is below the expected range. The engine may have reduced power.
Possible Causes
- APP sensor 2 failed low
- Wiring shorted to ground
- APP sensor connector issue
- Accelerator pedal mechanical fault
- ECM input circuit fault
Troubleshooting Steps
- Step 1: Connect an OBD-II scan tool and read all stored DTCs and freeze frame data
All DTCs and freeze frame data are retrieved - Step 2: Inspect the related sensor or actuator wiring for damage, corrosion, or loose connections
Wiring and connectors are in good condition - Step 3: Use a digital multimeter to check sensor voltage, resistance, and reference signals per manufacturer specifications
Values are within specified range - Step 4: Perform component-level testing of the suspected sensor or actuator
Component passes or fails definitively - Step 5: Clear codes and road test to verify repair
Code does not return and system operates normally
How to Reset
To reset code P1203: 1) Repair the underlying fault. 2) Use an OBD-II scan tool to clear the DTC. 3) Perform a drive cycle to verify the monitor completes. 4) If the code returns, further diagnosis is needed.
Frequently Asked Questions
- Q: What does OBD-II code P1203 mean?
Code P1203 indicates: Accelerator Pedal Position Sensor 2 Circuit Low. This is a GM manufacturer-specific diagnostic trouble code.
- Q: Is code P1203 serious?
Severity: Major. Immediate attention is recommended to prevent further damage.
- Q: Can I drive with code P1203?
It is not recommended to drive with this code active as it may cause further damage.
- Q: How do I fix code P1203?
Diagnose the Throttle system, check wiring and connectors, test the related sensor or actuator, and replace faulty components as needed.
Source: OBD-II Manufacturer Extended Codes / SAE J2012 / OBD-Codes.com
Category: OBD-II