P1493
Battery Temperature Sensor Voltage Too Low.
- Dodge
- Powertrain
- Manufacturer code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 1
- Defined byThe manufacturer
- 4
- AreaAuxiliary emission controls
- 93
- FaultThe specific fault in that area
What it means
P1493 on a Dodge means the powertrain control module has seen the battery temperature sensor signal voltage below its expected range. The module uses this sensor to adjust charging voltage to suit battery temperature, so a low reading suggests a short to ground, a faulty sensor or a wiring fault. Where the sensor is fitted and how it is wired depends on the model and engine.
Symptoms
- Charging system or battery warning light on
- Battery undercharged or repeatedly flat
- Battery overcharged, with a strong smell or swollen case in severe cases
- Malfunction indicator lamp illuminated
- Poor or slow cranking in cold weather
- Charging voltage that looks wrong on a scan tool or voltmeter
Possible causes
- Faulty battery temperature sensor (internal short or drift)likely
- Sensor signal wire chafed or shorted to groundlikely
- Corroded, loose or damaged sensor connector or terminalslikely
- Damaged or wet wiring harness near the battery tray or under the batterypossible
- Poor or missing sensor reference or ground circuit connectionpossible
- Faulty powertrain control modulerare
How to diagnose
- Read the stored codes and freeze frame data, noting whether the code is current or history, and check for any related charging system codes
- Check the battery condition and state of charge, and measure the charging voltage with the engine running
- Inspect the battery temperature sensor, its connector and the harness for damage, corrosion, moisture or chafing
- Compare the sensor temperature reading on a scan tool with the actual battery temperature, once the car has sat cold for several hours
- With the connector unplugged, check the sensor resistance against the manufacturer specification for the model, and see if the code changes to a high-voltage code
- Check the signal wire for a short to ground and for continuity back to the powertrain control module, using the wiring diagram for the specific vehicle
- Check the reference voltage and ground at the sensor connector
- Wiggle the harness while monitoring the sensor reading to find intermittent faults
How to fix
- Replace the battery temperature sensor if its resistance is out of specification
- Repair or replace any chafed, shorted or damaged wiring
- Clean or replace corroded connector terminals and secure the connector properly
- Restore a poor reference or ground connection
- Replace the powertrain control module only after all wiring and sensor faults are ruled out, following the manufacturer procedure
- Clear the code after repair and confirm it does not return on a road test
Can I keep driving?
The car can usually be driven short-term, but the charging voltage may be wrong, which can leave the battery flat or overcharge and damage it. Get it checked soon, and avoid long journeys if the battery or charging warning light is on.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.