What does it mean?
P1152 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: HO2S Heater Circuit Current Malfunction .
Symptoms
- Malfunction indicator lamp on, sometimes with a fuse blowing repeatedly
- Slow warm-up of the affected sensor and extended open loop running
- Higher fuel consumption during short journeys
- A faint burning smell if the harness has contacted the exhaust
- Readiness monitors staying incomplete
Likely causes
- Heater wire shorted to ground where the insulation has rubbed through against a bracket or shield
- Internal short inside the sensor heater winding, causing excessive current draw
- Melted harness section where the pigtail has fallen onto the exhaust pipe
- Water intrusion into the connector creating a low resistance path between pins
- Shorted heater in one sensor loading a supply shared with another sensor
- Damaged low-side driver in the PCM (powertrain control module) after a previous short
- Poor repair joint that has corroded and now changes resistance with temperature
How to fix it
- Inspect the sensor pigtail along its full length for melting, chafe marks and contact with hot components
- Disconnect the sensor and measure resistance from each heater pin to ground; a low reading means a short
- Measure heater element resistance across its pins and compare with the specified value
- Check the connector for water and corrosion, and dry and reseal it if moisture is present
- With the sensor unplugged, check whether the fuse still blows to separate a harness short from a sensor short
- Repair or replace the damaged harness section and secure it clear of the exhaust
- Replace the sensor if its heater is internally shorted, then confirm normal heater operation and fuse integrity