Guide To P2403 OBD Error Code Solutions

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P2403 is a generic powertrain code, which applies to OBD-II equipped vehicles. Although generic, the specific repair steps may vary depending on make/model.The EVAP System allows fuel tank vapours to be purged into the engine and burnt rather than expelled into the atmosphere as harmful emissions. The EVAP system contains a pressure sensor to check the integrity of the system. The input from the pressure sensor is acknowledged by the PCM in terms of voltages and any anomaly more than a certain period of time is treated as an error.

The evaporative emission (EVAP) control system pressure sensor is used for on board diagnosis of the EVAP system itself to check for leaks and does not initiate or control changes to the EVAP purge or vent valve operations. It detects and measures pressure in the purge line of the EVAP system. The pressure sensor’s output voltage increases as the pressure in the purge line increases, and the sensor voltage output is monitored by the powertrain control module (PCM).

This OBD code indicates that the leak detection pump portion of the EVAP control system is no longer functioning properly. The EVAP system consists of components including (but not limited to) the gas cap, fuel lines,charcoal canister, purge valve, system pressure and flow sensors, electrical wiring and connectors, vacuum lines, the fuel tank, and fuel vapor hoses.

What causes this problem with the Evaporative Emission System Leak Detection Pump Sense Circuit/Open?

• Open on Leak Detection Pump circuit wiring
• Short to voltage on LDP sensor signal
• Abnormally high pressure in fuel tank due to blockage
• LDP sensor connector loose or damaged
• Loss of ground to the sensor
• Purge control solenoid failure
• Damaged purge solenoid

1. Engine Control Module - Dead cells in batteries can cause a failure in the engine control module. Many times a battery is left in the rig long after a cell has died. This would affect the grounding in the car battery.
2. Powertrain Control Module - If there are some faults in the PCM, then it may throw off the timing and fuel settings of the engine, which can negatively affect the performance. A flawed PCM may cause the vehicle to experience a reduction in fuel efficiency, power as well as acceleration.
3. Exhaust Gas Recirculation Valve - Bad EGR valve can cause many performance issues. Common signs include engine performance issues like decreased power and acceleration, rough idle, and the Check Engine Light coming on. Thus, replace faulty EGR valve now!
4. Electronic Control Unit - Do you know that the poor performance or unexplained drops in fuel economy or efficiency are often associated to onboard car computer problems, or defective ECU issues?
5. Diagnostic Tools - Use factory grade diagnostic tools to resolve OBD code P2403 error. Buy new diagnostic tools and equipment for us.
6. Fluid Pump Control Module - If the control module is faulty, the pump will not be able to work properly and will not be able to transfer fluid to the transmission and hydraulic system efficiently. Thus, replacements are in order.
7. Engine Coolant Temperature Sensor - One major symptom of defective engine coolant temperature sensor is an overheating car engine. This can also cause engine misfiring. Take care of your car engine coolant temperature sensor and replace it if needed.
8. Catalytic Converter - Catalytic converters at fault will lead to dropped fuel efficiency and performance along with increased emissions. Thus replace faulty parts now!
9. Mass Air Flow Sensor - A faulty mass airflow sensor will cause problems similar to low compression or low vacuum, and will also show symptoms similar to when your vehicle has low fuel pressure from a faulty fuel pump. Thus, replace damaged/faulty MAF sensor today!
10. Heated Oxygen Sensor - A faulty sensor will not function properly and not analyse the air to fuel ratio in the exhaust. Visit us today to replace damaged oxygen sensors.
11. EVAP Leak Detection Pump - The LDP works to find leaks in a vehicle's fuel lines, with a focus on evaporative control systems (EVAP). Government regulations require leak detection testing to minimize harm to the public. Vehicle owners also benefit from these tests. Identifying and closing leaks will help maintain optimal vehicle performance.
12. Vapor Canister Valve - The canister purge valve, also commonly referred to as the purge valve, is an important component of your Evaporative Emission Control (EVAP) system. This system restricts the fuel vapours created in your fuel tank from escaping into the atmosphere by trapping them in a charcoal canister.
13. Vapor Canister Purge Solenoid - The canister purge solenoid is an emissions control component that is commonly found on the evaporative emission control system (EVAP) of many modern vehicles. Modern vehicles are equipped with an EVAP system that works to reduce the evaporative emissions pollution that can come from the vehicle’s fuel tank, which is released in the form of vapors. The EVAP system traps this vapor in a charcoal canister and recirculates it for use as fuel for the engine and prevented from polluting the environment.

Our main motive is to achieve customer satisfaction and that’s why we will help you to diagnose P2403 code by mentioning some major symptoms below:

Common Symptoms

• Check Engine Light On
• Noticeable fuel odour caused by the release of fuel vapours
• Reduced fuel economy

Have a look at some ways with which you can correct the P2403 code:

• Replacement of faulty/damaged wiring
• Replacement of faulty connections
• Replacement of EVAP pressure sensor and/or FTP sensor.
• Replacement of the purge control solenoid and purge valves
• Replacement of fuel caps
• Replacement of leak detection pump motor
• Replacement of broken hoses and charcoal canister

There is no need to get strained if your OBD Code is still flashing up as we are here at your service. Have a look at our superior variety of PCM, EVAP System, Intake Manifold, Pressure Sensor, Flow Sensor, Purge Control Solenoid, Pump Motor, Fuel Cap, Connectors, Charcoal Canister and many more. Now all your problems would vanish within no time.

Here are some steps which you should follow in order to diagnose this fault code P2403:

Locate the EVAP canister under your vehicle. It may be attached to the fuel tank or it may be separate from the fuel tank with hoses running to the fuel pump at the fuel tank. Check that the EVAP control system pressure sensor’s connector is fully seated and clipped in.

Inspect the sensor connector for corrosion at the wires. Disconnect the sensor and inspect the pins in the terminal to ensure they are clean and moisture free. Trace the wiring from the sensor back to determine if there are any breaks swollen spots on the wiring insulation that can indicate corrosion inside the wire. You may have to remove loom or electrical tape to inspect the wiring.

With a multimeter, verify your reference wire has 5 volts and check the continuity of the ground circuit. Probe the sensor signal wire with a multimeter set to read voltage. With the key in the on position but the engine not running, read a voltage value somewhere around 3 volts. Remove the hose attached to the EVAP pressure sensor and apply vacuum with a vacuum tester, monitoring changes in voltage on multimeter. If the voltage changes with vacuum applied, the sensor is operating. If the voltage doesn’t change with vacuum applied, the sensor is faulty.

If using a scan tool, access the EVAP pressure sensor reading in freeze frame data with a scan tool. The key must be in the on position with the engine off. The normal reading from the EVAP pressure sensor should be roughly 3 volts and should never exceed 4.5 volts. If the code P2403 is set in the ECM and the voltage is reading in the normal value range, it is likely have an intermittent problem.

Next, perform a wiggle test on the wiring to determine if there is a communication problem from the sensor to the ECM. Wiggle along the length of the circuit, monitoring the reading on your scan tool to see if there are fluctuations in the voltage. If the voltage spikes or drops off while you are wiggling a section of wire, you likely have a break in the wire that needs to be repaired.

If the high voltage disappears when the sensor is unplugged, the ground circuit is good, and the reference voltage is correct, that there is a blockage in an EVAP purge system hose. Disconnect the hoses from the EVAP purge valve and blow compressed air through them to make sure they are free-flowing. If there is a blockage, replace the hose.

Common Mistakes When Diagnosing the P2403 Code

Always check for the following components;

• Fuel Tank Sending Unit defects
• Defective or damaged Fuel Tank
• EVAP system wiring, or connector faults
• Carbon Canister faults
• Faults in the LDP, purge valve and solenoids
• Defective Canister Vent Valve which might not open