garajizOBD-II code · manufacturer-specific
P1138
HO2S Insufficient Switching Sensor 1
- System
- P1 — Powertrain (manufacturer-specific)
- Severity
- Minor (2/5)
- Can I keep driving?
- Usually safe to drive
What does P1138 mean?
P1138 is defined as “HO2S Insufficient Switching Sensor 1”.
You can usually keep driving, but have it checked soon so a small fault doesn’t become a bigger one.
Manufacturer-specific meanings
The same code can mean something different on some makes.
- Buick, Cadillac, Chevrolet, Chrysler, GM, GMC, Oldsmobile, Saturn: HO2S Bank 1 Sensor 2 Rich Or High Voltage
- Mazda: HO2S Bank 1 Sensor 2 Signal Above 0.45v AF Ratio Too Rich
- Citroen, Diğer, Peugeot: Lack Of HO2S12 Switch - Sensor Indicates Rich
- Jaguar: Lack Of HO2S12 Switches Sensor Indicates Rich
- Ford, Lincoln, Mercury: Lack of Downstream Heated Oxygen Sensor Switch Sensor Indicates Rich Bank 1
- Volkswagen: Long Term Fuel Trim Add Fuel Bank 2 System Too Lean
- BMW: O2 Sensor Heater Circuit Low Voltage Bank 1 Sensor 2
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This page is general information; an exact diagnosis needs measurements and a technician’s check.