Back to 2003 Mazda B2300

2003 MAZDA B2300

2.3L I4FWDAUTOMATICgas
Repairs0Labor471Torque2462Fluid6DTC713Battery0Maintenance0Recalls0
P0115moderate severityPowertrain

Engine Coolant Temperature (ECT) Sensor 1 Circuit

on 2003 Mazda B2300 2.3L I4 · FWD

What this code means

General malfunction in the engine coolant temperature sensor circuit.

Symptoms

  • Check Engine Light
  • Poor fuel economy
  • Hard starting
  • Incorrect temp gauge reading
  • Fans not operating correctly

Common causes

  • Faulty ECT sensor
  • Wiring damage
  • Corroded connector
  • Low coolant level

Diagnostic steps

  1. Test ECT resistance at known temperature
  2. Inspect wiring
  3. Check coolant level
  4. Compare ECT to IAT at cold start

Repair notes

Replace ECT sensor or repair wiring. Verify coolant level.

Other Powertrain codes on this vehicle

Building an app?
Free API access to all this data — 50 requests/day, no card required.
Get an API key →
Run a shop?
Manage repairs, estimates, and customers with ShopBase — $249/mo, all features included.
Try ShopBase →