Fix P0453: Mechanic’s solutions that WORKED

The P0453: Evaporative Emission Control System Pressure Sensor High Input indicates a problem with the Evaporative Emission Control System’s pressure sensor, specifically that the input signal is too high. This sensor monitors the pressure within the fuel system to detect leaks and ensure efficient emissions control. A high input signal might mean the sensor is faulty or there’s an issue in the wiring circuit.

P0453 quick overview

Meaning	P0453: Evaporative Emission Control System Pressure Sensor High Input
Is it serious?	This code is moderately serious as it can affect the vehicle’s emissions system, but it typically does not cause immediate drivability issues.
Possible causes	– Faulty or failing EVAP pressure sensor – Damaged or corroded wiring and connectors to the sensor – Short circuit or open circuit in the EVAP system wiring – Possible issues with the vehicle’s PCM (Powertrain Control Module)
How to diagnose?	Inspect EVAP Pressure Sensor: Check the condition and connections of the EVAP pressure sensor. Check Wiring and Connectors: Examine wiring and connectors for damage, corrosion, or loose connections. Monitor Sensor Voltage: Use a diagnostic scanner or multimeter to monitor the voltage from the pressure sensor. Test for Wiring Continuity: Check for continuity and shorts in the wiring between the sensor and PCM. Evaluate PCM Functionality: If other diagnostics are inconclusive, assess the PCM for potential faults.

How to fix P0453 – learn from mechanics

I looked into P0453 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Ford

Vehicle Information: 1997 Ford Explorer XL 4.0L

Issue + Repair History:

• MIL Lamp on immediately upon startup after a used motor was installed.
• Codes P0443 and P0453 stored for the EVAP system.
• Motor replacement was from the same year and model.
• Double-checked all EVAP connections, lines, charcoal canister, evap solenoid, gas cap, and fuel tank connections.

Computer Codes & Descriptions:

• P0443: EVAP System Purge Control Valve Fault
• P0453: EVAP System Pressure Sensor High

Suggestions to Fix Issue:

• Run the Ford KOEO (Key On Engine Off) test to determine if the codes are active.
• Check if similar connectors for the EVAP and A/C systems could be mistakenly swapped.
• Inspect the wiring and connections for the vapor management valve and fuel tank pressure valve.
• Consider replacing the purge flow sensor and solenoid as an assembly.

Final Fix:

• The issue was due to the engine wiring harness from a Ranger 4.0L, which was missing a wire to the solenoid on the charcoal canister.
• Replaced the wiring harness with the correct one, resolving the issue.

Case #2: Lexus

Vehicle Information: 2004 Lexus RX330 3.3L

Issue + Repair History:

• Recurring code P0453.
• Checked fuel tank pressure readings with no changes observed.

Computer Codes & Descriptions:

• P0453: Evaporative Emission Control System Pressure Sensor/Switch High Input

Suggestions to Fix Issue:

• Check all vacuum lines, especially those around the airbox.
• Review TSB#EG008-04 for detailed instructions.
• Actuate the purge valve to observe changes.
• Inspect the wiring and condition of the vapor pressure sensor on top of the fuel tank.
• Look for possible rodent damage or nests on top of the tank affecting hoses and wiring.

Final Fix:

• Discovered missing sections of the wiring loom near the vapor pressure sensor.
• Ordered and replaced the wiring harness, along with the vapor canister and filter.
• The repairs resolved the issue, eliminating the recurring P0453 code.

Case #3: Kia

Vehicle Information: 1997 Kia Sportage 2.0L

Issue + Repair History:

• MIL lamp on with Code PO453.
• Code persists after clearing and completing a drive cycle.
• Found loose inlet hose clamp on fuel tank, and RTV used on sensor and seal to the sending unit.
• Fuel pump replaced twice previously by an unqualified individual.
• Repaired EVAP system 2 months ago, including replacing canister and purge valve.

Computer Codes & Descriptions:

• PO453: Evaporative Emission Control System Pressure Sensor High Input

Suggestions to Fix Issue:

• Check the resistance of the fuel tank pressure sensor.
• Confirm 5.0 volt reference and good ground for the fuel tank pressure sensor.
• Check the output voltage signal of the fuel tank pressure sensor.
• Inspect for possible electrical circuit issues or a faulty PCM.
• Consider looking at the 1998 model in repair databases for additional guidance.

Final Fix:

• Determined the issue was with the pressure control sensor.
• Replaced the sensor, which resolved the issue.

Case #4: Ford

Vehicle Information: 1998 Ford Ranger Splash 4.0L

Issue + Repair History:

• Code P0453 initially detected.
• Replaced the pressure sensor but the code reappeared.
• Induced reverse voltage in testing, leading to PCM replacement.
• Replaced one wire and the PCM, but the issue persisted.
• Scan tool showed FTP PID at 5.12V constantly, changing only when jumpering wires at the sensor.

Computer Codes & Descriptions:

• P0453: Tank Pressure High

Suggestions to Fix Issue:

• Check for open connections, loose pins, and high resistance in the circuit.
• Verify voltages and drops in the circuit, including the sensor return wire.
• Consider the possibility of a ground issue or short to power in the FTP signal.
• Measure the readings directly at the sensor for proper voltage distribution.

Final Fix:

• Found an open in the wire above the gas tank for the sensor return wire.
• Repairing this wire resolved the issue with the P0453 code.

Case #5: Chevrolet

Vehicle Information: 1998 Chevrolet C1500 Suburban LS 5.7L

Issue + Repair History:

• MIL Lamp on with codes P0452 and P0453.
• Initially replaced the pressure sensor; however, the issue persisted.
• Retested and considered replacing the PCM.
• Tested all wiring from PCM to sensor and replaced one wire.
• Replaced PCM but still faced the same code.
• FTP PID in the scanner read 5.12V constantly.

Computer Codes & Descriptions:

• P0452: EVAP Pressure Sensor Low Input
• P0453: EVAP Pressure Sensor High Input

Suggestions to Fix Issue:

• Check for open connections and high resistance in the circuit.
• Monitor voltage on the signal wire after clearing codes.
• Inspect for other sensors or harness issues in the circuit.
• Verify sensor operation with the system pressurized.
• Check sensor connection and consider using an AC Delco unit.
• Test sensor signal voltage with DVOM and scan tool to ensure PCM can read data.

Final Fix:

• Found an open in the wire above the gas tank for the sensor return wire.
• Fully connected the sensor connector, which was not completely attached.
• Replaced the sensor and ensured it was fully connected.
• The issue was resolved, eliminating the P0452 and P0453 codes.

Advice	Brief Description of Diagnostic Step
Check Pressure Sensor	Inspect and potentially replace the EVAP pressure sensor if it shows signs of failure or damage.
Inspect Wiring and Connectors	Examine the wiring and connectors for any signs of damage, corrosion, or loose connections.
Monitor Sensor Voltage	Use a diagnostic tool or DVOM to monitor the voltage from the pressure sensor.
Verify Ground and Reference Voltage	Check for proper ground and reference voltage at the sensor to ensure circuit integrity.
Test for Open or Short in Wiring	Look for any open or short circuits in the wiring between the sensor and the PCM.
Ensure Proper Sensor Connection	Make sure the pressure sensor is fully and correctly connected.
Consider Potential PCM Issues	If other diagnostics fail, evaluate the PCM for potential faults related to the code.