P2402
Evaporative Emission System Leak Detection Pump Control Circuit High
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The P2402 code indicates that the PCM has detected a higher-than-expected voltage on the EVAP leak detection pump control circuit. This is the opposite of P2401 — instead of too little voltage, the circuit is reading too high. This usually points to a short to voltage in the wiring or an internal pump failure.
As with other EVAP system codes, this will not affect your vehicle's drivability. The engine will run fine and you should not notice any performance changes. The main concern is that the EVAP leak detection system is non-functional, so any fuel vapor leaks will go undetected. Your vehicle will fail emissions testing.
Diagnosis should start with a careful inspection of the wiring harness leading to the leak detection pump. Look for rubbed-through insulation where wires cross metal brackets or body panels. Check the connector for signs of water intrusion or corrosion. If the wiring is intact, the leak detection pump is likely the problem. This is a commonly failing part on vehicles equipped with this system, particularly on Chrysler, Dodge, and Volkswagen models.
Severity
Symptoms
- •Check Engine Light is on
- •Vehicle will fail emissions testing
- •Possible faint gasoline odor
- •No noticeable drivability problems
- •EVAP system leak monitoring is disabled
Likely Causes
The pump motor may have an internal short causing it to draw excessive current, creating a high voltage reading on the circuit.
A wire in the LDP circuit has its insulation worn through and is touching a voltage source, causing a high reading.
Water intrusion or corrosion in the LDP connector can create abnormal circuit conditions.
If the EVAP pump is controlled through a relay, a stuck-on relay can cause continuous high voltage on the circuit.
A PCM driver circuit failure could send excessive voltage to the pump control circuit.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Replace EVAP leak detection pump
- Repair short circuit in wiring harness
- Clean or replace corroded connectors
- Replace EVAP pump relay if applicable
Shop Parts
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