Back to 1998 Mazda B2500

1998 MAZDA B2500

2.5L I4FWDAUTOMATICgas
Repairs0Labor469Torque4906Fluid6DTC640Battery0Maintenance0Recalls0
P0036low severityPowertrain

HO2S Heater Control Circuit Bank 1 Sensor 2

on 1998 Mazda B2500 2.5L I4 · FWD

What this code means

The PCM detected a malfunction in the heater circuit of the downstream heated oxygen sensor (Bank 1, Sensor 2).

Symptoms

  • Check Engine Light
  • Failed emissions test
  • Poor catalyst monitoring

Common causes

  • Faulty O2 sensor heater
  • Blown fuse
  • Wiring issue

Diagnostic steps

  1. Check fuse
  2. Test heater resistance
  3. Inspect wiring
  4. Check PCM output

Repair notes

Replace downstream O2 sensor or repair wiring.

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 →