Diagnostic article Generic OBD-II
P2234: bank-two heater coupling is evaluated under controlled sensor conditions
GM P2234 uses filtered bank-two sensor current change and qualified heater, temperature and mixture states to evaluate heater influence.
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Documented application
GM 2009 09OBDG13 2-Mode Hybrid Diagnostics, cited bank-two primary sensor heater coupling monitor only. Document-level evidence does not establish per-code vehicle, engine or wiring applicability.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P2234 is the heater-coupling diagnostic for the bank-two primary oxygen sensor in this GM hybrid table. The monitored quantity is a filtered sensor-current change, not merely heater resistance or the presence of a general mixture fault.
The heater and sensor must be in the right state
The source lists a current change of at least 190 microamps, with a fifteen-second evaluation. It also requires qualified exhaust and sensor-ceramic temperatures, battery voltage, engine load and fuel-system state. Heater duty cycle is restricted to the stated intermediate range rather than simply any on command.
Additional settling conditions follow heater power-stage switching, and the diagnostic scheduler must enable the test. These details matter because a normal switching transient or an unqualified warm-up observation should not be treated as the documented coupling failure.
Preserve bank identity and operating context
A technician should retain the bank-two signal and heater context from the event. Evidence for bank one does not automatically identify the source of a bank-two report, even when both sensors use similar technology. The full code and actual vehicle mapping remain necessary.
The table does not isolate an internal sensor short from a wiring problem or prescribe replacement of both sensors. It supplies monitor evidence that must be investigated with the matching service procedure. Verification should demonstrate the relevant qualified heater-coupling evaluation, rather than only a cleared code. Physical work must also account for hot exhaust components and the correct electrical isolation conditions.
Source and applicability
GM 2009 09OBDG13 2-Mode Hybrid Diagnostics, cited bank-two primary sensor heater coupling monitor only. Document-level evidence does not establish per-code vehicle, engine or wiring applicability.
General Motors source, physical page 135 · General Motors source, physical page 136
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 2 Sensor 1
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT