Back to 2003 Mazda B2300

2003 MAZDA B2300

2.3L I4FWDAUTOMATICgas
Repairs0Labor471Torque2462Fluid6DTC713Battery0Maintenance0Recalls0
P0037low severityPowertrain

HO2S Heater Control Circuit Low Bank 1 Sensor 2

on 2003 Mazda B2300 2.3L I4 · FWD

What this code means

The voltage in the Bank 1 Sensor 2 O2 heater circuit is lower than expected.

Symptoms

  • Check Engine Light
  • Poor catalyst monitoring

Common causes

  • Short to ground
  • Faulty sensor
  • Corroded connector

Diagnostic steps

  1. Test heater voltage
  2. Check for shorts
  3. Test resistance

Repair notes

Repair wiring or replace sensor.

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 →