P1493

What it means

P1493 on a Pontiac means the powertrain control module has seen the battery temperature sensor signal voltage fall below its expected range. The module uses this input to adjust charging voltage and some other strategies, so a low reading usually points to a short to ground in the circuit, a faulty sensor, or a wiring or connector fault. Exact sensor location and circuit layout depend on the model and engine.

Symptoms

• Check engine light or service engine soon light on
• Battery warning light or charging system message in some cases
• Battery undercharging or overcharging, or a flat battery after short trips
• Slow cranking or hard starting if the battery is not charging properly
• No noticeable symptoms other than the stored code

Possible causes

• Battery temperature sensor circuit shorted to ground (chafed or pinched wiring)likely
• Faulty battery temperature sensor reading falsely cold or low voltagelikely
• Damaged, corroded or wet connector at the sensor or battery harnesspossible
• Sensor signal wire shorted to the sensor ground or to another low-voltage circuit within the harnesspossible
• Poor reference or ground connection affecting the sensor circuitpossible
• Faulty powertrain control modulerare

How to diagnose

1. Read the stored codes and freeze frame data, note any charging system or other sensor codes, then record whether P1493 returns after clearing.
2. Check the battery condition, terminals and charging voltage to see whether the charging system is behaving normally.
3. Locate the battery temperature sensor using the model-specific service information and inspect it and its wiring for damage, rubbing, heat or corrosion.
4. Inspect the connectors at the sensor and the control module for moisture, bent pins and poor terminal tension.
5. With a scan tool, view the battery temperature reading and compare it with actual battery or ambient temperature on a cold car.
6. Unplug the sensor and check live data: the reading should change to a high or open-circuit value if the wiring is sound, and stay low if the wiring is shorted to ground.
7. Measure the sensor resistance and compare it with the specification for your model, and test the signal wire for continuity and for shorts to ground.
8. Check the reference voltage and ground at the harness connector using the wiring diagram for the specific engine.

How to fix

• Repair or replace damaged wiring that is shorted to ground, and secure the harness away from sharp edges and heat.
• Replace the battery temperature sensor if its resistance is out of specification or it reads incorrectly.
• Clean or replace corroded or damaged connectors and terminals.
• Repair any poor ground or reference supply fault found in the circuit.
• Replace or reprogram the powertrain control module only after all wiring and sensor faults are ruled out and the fault is confirmed to be internal.

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
• P1493PlymouthBattery Temperature Sensor Voltage Too Low

Nearby codes

• P1492PontiacBattery Temperature Sensor Voltage Too High
• P1494PontiacLeak Detection Pump Switch Or Mechanical Fault