---
title: "B1503 Toyota"
slug: b1503
collection: obd2-codes
code: B1503
url: https://fixmycar.pk/obd2-code-list/b1503/
---
B1503 Diagnostic Trouble Code (DTC) is stored when the Combination Meter Assembly (metre circuit plate) detects a malfunction in the Engine Coolant Temperature Sensor that is linked to the Combination Meter Assembly (metre circuit plate) through a direct connection.

When IG voltage is 9.5 V or more and the following condition is detected:

1.Water temperature sensor operation malfunction  
2.Water temperature sensor circuit open or short  
3.Engine coolant temperature is 120°C (248°F) or more