Code Definition

P1158 — O2 Sensor Rich or High Voltage (Bank 2 Sensor 2), or Engine Overtemperature Protection Fault

System: Powertrain  |  Type: Manufacturer-Specific  |  Make: GM

About P1158

P1158 is a manufacturer-specific powertrain diagnostic trouble code recorded for GM vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1158 is stored, the module has detected a signal or supply voltage higher than the expected operating range; a bank-specific fault, meaning it applies only to one cylinder bank of a multi-bank engine; and a sensor-related fault — the reported value from the named sensor is out of spec.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

P1158 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

This General Motors specific code has two platform dependent definitions, the Bank 2 Sensor 2 downstream oxygen sensor reading rich or high voltage, or an Engine Overtemperature Protection fault. In the oxygen sensor form, similar to P1157, the post catalyst sensor on Bank 2 stays biased high rather than at the steadier voltage expected from a healthy rear sensor, pointing to contamination, a wiring short or a rich exhaust. In the overtemperature form, the code relates to the strategy that protects the engine when coolant temperature climbs too high, where the PCM may shut down cylinders in ro...

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