P0452

EVAP System Pressure Sensor/Switch Circuit Low

Car Fault Codes Emissions & exhaust

Can you still drive? Yes, normally

Who can fix it? Needs a workshop

Typical repair time 30 minutes – 3 hours

Typical cost SAR 100 to 900

What it means

The engine computer has detected that the fuel tank pressure sensor signal is below its allowed minimum. This usually means the signal wire is shorted to ground, the reference voltage is missing or the sensor has failed, so the computer cannot test the EVAP system.

Symptoms4

Check engine light on.
Usually no driving symptoms.
EVAP self-test stops running.
Failed emissions test.

Possible causes5

Signal wire shorted to ground from chafing under the vehicle.
Open reference voltage supply to the sensor.
Failed fuel tank pressure sensor.
Connector corroded by water and dust.
Short in another sensor sharing the same reference circuit.

How to diagnose5

Watch the sensor reading on a scan tool and compare it with the manufacturer specification.
Measure the reference voltage and ground at the sensor connector.
Unplug the sensor and watch the reading; if it stays low, the fault is in the wiring.
Inspect the wiring under the vehicle for chafing or damage.
If other sensor codes are present, check the shared reference circuit.

How to fix5

Clean or replace the connector.
Repair the wire shorted to ground and secure it away from chafe points.
Repair the reference circuit or the sensor pulling it down.
Replace the tank pressure sensor if it is proven faulty.
Clear the codes and confirm the reading is back in range.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low for a wire or connector fault, and rises if the fuel tank must be lowered to replace the sensor.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Does this code affect fuel economy?

No. It only concerns the EVAP test and does not affect the fuel mixture or engine performance.

Why check the wiring before replacing the sensor?

The sensor wiring runs under the vehicle and is exposed to chafing and water, so the short is often in the wiring rather than the sensor.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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