Open circuit or high resistance in the battery temperature sensor signal or ground wiring; Corroded, loose or damaged sensor connector; Faulty battery temperature sensor; Signal wire shorted to a voltage supply; Damage to the wiring from heat, chafing or previous repair work near the battery or tray; Fault inside the powertrain control module.

P1492

Battery Temperature Sensor Voltage Too High.

Plymouth
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

On Plymouth models, P1492 means the powertrain control module saw the battery temperature sensor signal voltage higher than the expected range. The sensor is a thermistor used to help the PCM adjust charging voltage to battery temperature. A high voltage usually points to an open circuit, a poor connection or a faulty sensor. The exact sensor location and test values depend on the model and engine.

Symptoms

Charging system or check engine warning light on
Battery undercharged or overcharged in some conditions
Slow or weak starting, particularly in cold weather
Alternator output seems poor or inconsistent
No obvious driveability problems in many cases

Possible causes

Open circuit or high resistance in the battery temperature sensor signal or ground wiringlikely
Corroded, loose or damaged sensor connectorlikely
Faulty battery temperature sensorlikely
Signal wire shorted to a voltage supplypossible
Damage to the wiring from heat, chafing or previous repair work near the battery or traypossible
Fault inside the powertrain control modulerare

How to diagnose

Read the stored codes and freeze frame data, and note whether any charging or battery codes are also present.
Check the battery condition, terminals and charging voltage so any real battery or alternator problem is not missed.
Inspect the sensor, its connector and the wiring to the PCM for corrosion, damage, chafing and poor pin tension.
Check the live battery temperature reading against the actual battery temperature; a reading stuck at the extreme cold end suggests an open circuit.
With the ignition off and the connector unplugged, test the sensor resistance and compare it with the manufacturer's specification for your model.
With the ignition on, check the reference voltage and signal at the sensor connector against the wiring diagram.
Test the signal and ground wires for continuity, and for shorts to power or ground, as per the wiring diagram.
If the wiring and sensor test good, check the PCM power, grounds and connector before suspecting the PCM.

How to fix

Repair or replace damaged wiring and fix any open circuit or short to voltage.
Clean or replace a corroded or loose connector and terminals.
Replace the battery temperature sensor if its resistance is out of specification.
Repair any battery or charging system fault found during testing.
Replace or reprogram the PCM only after all other causes are ruled out and the manufacturer's procedure confirms it.

Can I keep driving?

Low severity

The car can normally be driven, but book it in soon because incorrect charging control could leave the battery undercharged or stressed over time. If the battery warning light comes on or starting becomes poor, get it checked sooner.

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