P202F - Reductant/Regeneration Supply Control Circuit Range/Performance
The P202F code indicates that the powertrain control module (PCM) has detected a malfunction in the reductant supply control circuit, which is responsible for delivering diesel exhaust fluid (DEF) to the selective catalytic reduction (SCR) system. This circuit includes the DEF pump, heater, and associated wiring. The 'Range/Performance' aspect means the signal from the circuit is outside expected parameters, often due to electrical issues or component failure. This can lead to improper DEF injection, affecting emissions and potentially triggering limp mode.
01. Most Common Causes
- Faulty DEF pump or heater
- Open or shorted wiring in the reductant supply circuit
- Corroded or loose electrical connectors
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Increased diesel exhaust fluid consumption
- Poor fuel economy
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Visually inspect the DEF pump, heater, and wiring for damage or corrosion.
Step 3: Test the resistance and voltage at the reductant supply control circuit using a multimeter.
Step 4: Check for technical service bulletins (TSBs) related to the vehicle model.
Step 5: If wiring is intact, test the DEF pump and heater per manufacturer specifications.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the vehicle may enter limp mode, reducing speed and potentially causing further damage to the SCR system.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on whether the issue is a simple wiring repair or requires replacement of the DEF pump or heater.