P1493

What it means

On Jeep vehicles P1493 means the powertrain control module has seen the battery temperature sensor signal voltage fall below the expected range. The module uses this sensor to adjust charging voltage to suit battery temperature, so a low signal usually points to a short to ground in the circuit or a faulty sensor. The location and design of the sensor vary by model and engine, so confirm the details for the specific vehicle.

Symptoms

• Charging system or check engine warning light on
• Battery undercharged or repeatedly going flat
• Battery overcharged, with signs of heat or swelling in extreme cases
• Hard starting, especially in cold weather
• Inconsistent or incorrect voltmeter reading on the dash

Possible causes

• Battery temperature sensor internally faulty (reading as a short)likely
• Sensor signal wire chafed or shorted to groundlikely
• Corroded, damaged or wet sensor connector causing a low voltage signalpossible
• Poor reference or ground connection in the sensor circuitpossible
• Heat or physical damage to the sensor or harness near the battery or traypossible
• Faulty powertrain control modulerare

How to diagnose

1. Read the stored codes and freeze frame data, noting whether other charging or sensor circuit faults are present, then record and clear the code to see if it returns.
2. Check the battery condition and state of charge, and test the charging system output, as a flat or failing battery can mimic the symptoms.
3. Visually inspect the battery temperature sensor, its connector and the harness along the battery tray for chafing, melting, corrosion or water ingress.
4. With the sensor connected, view live data for battery temperature and compare it with the actual ambient or battery temperature.
5. Disconnect the sensor and check the live reading and signal voltage at the harness; if the fault changes, suspect the sensor.
6. Measure the sensor resistance and compare it with the manufacturer's specification for the model.
7. Test the signal wire for a short to ground and check the reference and ground circuits for continuity back to the module.
8. Only once wiring and sensor are proven good, check the module power and grounds before considering the module itself.

How to fix

• Replace the battery temperature sensor if its resistance is out of specification or it reads as shorted.
• Repair or replace the chafed or shorted signal wire and secure it clear of sharp edges and heat.
• Clean or replace the corroded or damaged connector terminals and ensure the connector seats and seals correctly.
• Repair any poor ground or reference circuit connection found during testing.
• Replace the battery if it is found to be damaged or failing, then recheck the charging system.
• Replace or reprogram the powertrain control module only as a last resort after all circuit tests are passed.

Can I keep driving?

This code for other makes

• P1493DodgeBattery Temperature Sensor Voltage Too Low
• P1493NissanEVAP Canister Purge Control Valve Solenoid Valve
• P1493OtherRCNT Solenoid Circuit Malfunction
• P1493PlymouthBattery Temperature Sensor Voltage Too Low
• P1493PontiacBattery Temperature Sensor Voltage Too Low

Nearby codes

• P1492JeepBattery Temperature Sensor Voltage Too High
• P1494JeepLeak Detection Pump Switch Or Mechanical Fault