EVAP Leak Detection Pump Heater Control Circuit High
The P240C code indicates that the Powertrain Control Module (PCM) has detected a high voltage condition in the heater control circuit of the Evaporative Emission (EVAP) leak detection pump. This pump is part of the EVAP system, which prevents fuel vapors from escaping into the atmosphere. The heater helps the pump operate efficiently in cold temperatures. A high voltage reading suggests a short to power, a faulty pump, or a wiring issue.
1. Most Common Causes
- Faulty EVAP leak detection pump
- Short to power in the heater control circuit
- Damaged wiring or connector
- Corroded terminals
- Failed PCM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Possible fuel odor
- No noticeable drivability issues
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P240C and check for other EVAP codes.
Step 2: Visually inspect the EVAP leak detection pump and its wiring for damage, corrosion, or loose connections.
Step 3: Test the heater circuit voltage at the pump connector with a multimeter (should be battery voltage with key on).
Step 4: Check for shorts to power by disconnecting the pump and measuring voltage at the harness connector.
Step 5: If voltage is present when disconnected, repair the short; if not, replace the pump.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, it is generally safe to drive, but the Check Engine Light will be on and you may fail an emissions test. The EVAP system is not critical for engine operation.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, depending on whether the pump needs replacement (part cost $30-$100) or just wiring repair.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.