THE CODE DIRECTORY

Diagnostic code references — Page 48.

Browse canonical reference entries. Each definition keeps its own source and vehicle-applicability limits.

Buick / Cadillac +5

P1157

These are code references, not a list of confirmed faults on every vehicle. Read the source and applicability notes, then match the exact vehicle, year, engine and scan report.

HO2S Bank 2 Sensor 2 Lean System Or Low Voltage

Lack of Downstream Heated Oxygen Sensor Switch Sensor Indicates Lean Bank 2

Lack Of HO2S22 Switches Sensor Indicates Lean

Manifold Absolute Pressure Sensor Circuit Power Supply Malfunction

Fuel Trim Adaptation Additive Bank 1 Low

HO2S Bank 2 Sensor 2 Rich Or High Voltage

Lack of Downstream Heated Oxygen Sensor Switch Sensor Indicates Rich Bank 2

Lack Of HO2S22 Switches Sensor Indicates Rich

Manifold Absolute Pressure Sensor Circuit Range Performance

Fuel Trim Adaptation Additive Bank 1 High

HO2S Cross Counts Bank 2 Sensor 2

Fuel Trim Adaptation Additive Bank 2 Low

Manifold Temperature Sensor Circuit Short To Ground

Fuel Trim Adaptation Additive Bank 2 High

HO2S Heater Power Stage Circuit Bank 2 Sensor 2

Manifold Temperature Sensor Circuit Open/Short To B+

Fuel Trim Adaptation Additive Per Ignition Bank 1 Low

HO2S11 Circuit Fault Bank 1 Sensor 1

Fuel Temperature Sensor Circuit Short To Ground

Fuel Trim Adaptation Additive Per Ignition Bank 1 High

HO2S Bank 2 Sensor 3 Lean System Or Low Voltage

HO2S11 Slow Response Bank 1 Sensor 1

Fuel Temperature Sensor Circuit Open/Short To B+

Fuel Trim Adaptation Additive Per Ignition Bank 2 Low

HO2S Bank 2 Sensor 3 Rich Or High Voltage

HO2S11 Circuit Fault Bank 1 Sensor 1

Fuel Temperature Sensor Range Performance

Fuel Trim Adaptation Additive Per Ignition Bank 2 High

HO2S Cross Counts Bank 2 Sensor 2

HO2S11 Slow Response Bank 1 Sensor 1

Swirl Control Valve Control Vacuum Switch

Bank 1 Long Term Fuel Trim Range 1 Lower Lean Limit Exceeded

HO2S11 Heater Circuit Fault Bank 1 Sensor 1

Bank 1 Long Term Fuel Trim Range 2 Upper Rich Limit Exceeded

HO2S11 Heater Circuit VS+ Fault Bank 1 Sensor 1

Fuel Rail Sensor In-Range Low Failure

HO2S11 Label Circuit Low Voltage Fault Bank 1 Sensor 1

Closed Loop Control Bank 2

Fuel Rail Sensor In-Range High Failure

HO2S11 Label Circuit High Voltage Fault Bank 1 Sensor 1

HO2S Bank 1 Sensor 1 Circuit Fixed Bank 1 Sensor 1

Bank To Bank Fuel Trim Offset

ESO Engine Shut Off Solenoid Fault

HO2S11 Circuit Voltage Stuck At Mid-Range

HO2S Bank 1 Sensor 1 Circuit Fixed Bank 1 Sensor 1

Fuel System Lean During Acceleration

Rotor Sensor Fault

System Too Lean Banks 1 And 2 (Lean Fuel Fault)

Throttle Actuation Potentiometer Signal 2 Range Performance

Rotor Control Fault

System Too Rich Banks 1 And 2 (Rich Fuel Fault)

Throttle Actuation Potentiometer Signal 2 Signal Too Low

Rotor Calibration Fault

HO2S Bank 2 Sensor 1 Circuit Fixed Bank 2 Sensor 1

Throttle Actuation Potentiometer Signal 2 Signal Too High

Fuel Trim Adaptation Additive Bank 1 Malfunction

Cam Sensor Fault

System Too Lean Banks 1 And 2 (Suspect HO2S)

Fuel Trim Bank 1 Different Injection Times

Fuel Trim Adaptation Additive Bank 2 Malfunction

Cam Control Fault

System Too Rich Banks 1 And 2 (Suspect HO2S)

O2 Sensor Slow Response Bank 1

Cam Calibration Fault

Long Term Fuel Trim Too Lean Banks 1 And 2 (FMFR)

Rear Oxygen Sensor Correction

O2 Sensor Slow Response Bank 2

Synchronization Fault

Long Term Fuel Trim Too Rich Banks 1 And 2 (FMFR)

Oxygen Sensor Correction Behind Catalyst Bank 1 Limit Attained

O2 Sensor Signal Circuit Slow Switching From Rich to Lean Bank 1 Sensor 1

Long Term Fuel Trim Too Lean Banks 1 And 2 (AMFR)

Linear Oxygen Sensor Pump Current Open

O2 Sensor Signal Circuit Slow Switching From Rich to Lean Bank 2 Sensor 1

Long Term Fuel Trim Too Rich Banks 1 And 2 (AMFR)

Linear Oxygen Sensor Pump Current Short To Ground

O2 Sensor Signal Circuit Slow Switching From Rich to Lean Bank 1 Sensor 2

Fuel Delivery System Malfunction Low

Linear Oxygen Sensor Pump Current Short To B+

O2 Sensor Signal Circuit Slow Switching From Rich to Lean Bank 2 Sensor 2