Open circuit or high resistance in the sensor signal or ground wire; Corroded, loose or damaged connector at the battery temperature sensor; Faulty battery temperature sensor reading falsely low temperature; Signal wire shorted to a voltage supply; Damaged wiring from heat, chafing or battery acid exposure; Fault inside the powertrain control module.

P1492

Battery Temperature Sensor Voltage Too High.

Pontiac
Powertrain
Manufacturer code
Low severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
4: AreaAuxiliary emission controls
92: FaultThe specific fault in that area

What it means

P1492 on a Pontiac means the powertrain control module has seen the battery temperature sensor signal voltage sitting higher than expected. The module uses this sensor to estimate battery temperature and adjust charging voltage, so a high reading usually points to an open circuit, a poor connection or a faulty sensor. The exact sensor location and the way it is wired depend on the model and engine.

Symptoms

Check engine light on
Battery warning light or charging system warning in some cases
Battery undercharged or overcharged in extreme temperatures
Slow cranking or hard starting if the battery is not charging correctly
No obvious symptoms in many cases

Possible causes

Open circuit or high resistance in the sensor signal or ground wirelikely
Corroded, loose or damaged connector at the battery temperature sensorlikely
Faulty battery temperature sensor reading falsely low temperaturelikely
Signal wire shorted to a voltage supplypossible
Damaged wiring from heat, chafing or battery acid exposurepossible
Fault inside the powertrain control modulerare

How to diagnose

Read the stored codes and freeze frame data, and note any other charging or sensor codes
Check the battery condition, terminals and cables for corrosion and security
Inspect the battery temperature sensor, its wiring and connector for damage, corrosion or acid contamination
Use scan data to compare the battery temperature reading with the ambient temperature when the car is cold; a very low or implausible value suggests a fault
Check the sensor resistance against the manufacturer specification for the model and engine
With the sensor unplugged, check the reference voltage and ground at the connector using a multimeter
Test the signal wire for continuity back to the control module and for shorts to voltage
Clear the code and road test to see whether it returns

How to fix

Repair or replace damaged wiring and clean or renew corroded connector terminals
Replace the battery temperature sensor if its resistance is out of specification
Repair any short to voltage in the signal circuit
Replace the battery or its cables if corrosion or acid damage has affected the sensor circuit
Replace or reprogram the control module only after all wiring and sensor faults have been ruled out

Can I keep driving?

Low severity

The car can normally be driven while you arrange a repair. Have the battery and charging system checked soon, as incorrect charging control can shorten battery life.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.