P1493

What it means

P1493 on a Plymouth means the powertrain control module has seen the battery temperature sensor signal voltage fall below its expected range. The module uses this sensor to estimate battery temperature and adjust charging voltage. A low reading suggests a short to ground, a faulty sensor or a wiring problem in the sensor circuit.

Symptoms

• Check engine light on
• Battery warning light may come on in some cases
• Battery undercharged or repeatedly flat, especially in cold weather
• Battery overcharged, with signs such as swollen case or electrolyte loss, in some cases
• Charging voltage seems fixed or incorrect on a voltmeter
• Slow cranking after standing

Possible causes

• Faulty battery temperature sensor reading falsely low (internal short or failed element)likely
• Sensor signal wire chafed and shorted to groundlikely
• Damaged, corroded or loose connector at the sensor or control modulepossible
• Water or corrosion inside the sensor circuit pulling the voltage downpossible
• Faulty sensor reference supply or ground fault affecting the readingpossible
• Fault inside the powertrain control modulerare

How to diagnose

1. Read all stored codes and freeze frame data, then note whether the code is current or has returned after clearing
2. Check battery condition and state of charge, and measure charging system voltage with the engine running to see if it is plausible
3. Inspect the battery temperature sensor, its wiring and connectors for chafing, melting, corrosion, water ingress or battery acid damage
4. With live data, compare the battery temperature reading with the actual ambient temperature on a cold car; a very low or fixed value points to a short or sensor fault
5. Unplug the sensor and check whether the reading changes; if the value moves to the open-circuit extreme, the sensor or its connector is at fault
6. Measure the sensor resistance and compare it with the manufacturer specification for the model and engine, as the location and values vary
7. Check the signal wire for a short to ground and for continuity back to the control module, and check the reference and ground circuits
8. Only after the wiring and sensor are proven good, consider testing the control module

How to fix

• Replace the battery temperature sensor if its resistance is out of specification
• Repair or replace the damaged wiring section shorted to ground
• Clean or replace corroded or damaged connector terminals and seal them against moisture
• Correct any reference or ground circuit fault found during testing
• Replace or recharge the battery if it was damaged by incorrect charging, then recheck charging voltage
• Replace or reprogram the control module only if all other tests confirm it is faulty

Can I keep driving?

This code for other makes

• P1493DodgeBattery Temperature Sensor Voltage Too Low
• P1493JeepBattery Temperature Sensor Voltage Too Low
• P1493NissanEVAP Canister Purge Control Valve Solenoid Valve
• P1493OtherRCNT Solenoid Circuit Malfunction
• P1493PontiacBattery Temperature Sensor Voltage Too Low

Nearby codes

• P1492PlymouthBattery Temperature Sensor Voltage Too High
• P1494PlymouthLeak Detection Pump Switch Or Mechanical Fault