P0D49: Battery Charger 14 Volt Output Current Sensor Circuit Low

What it means

The ECM detects a low fault on the battery charger 14 volt output current sensor circuit. Reading cannot be used reliably for control.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

The battery charger's 14-volt output current sensor tells the control module how much low-voltage current the charger is supplying. P0D49 sets when the sensor signal is below the expected electrical range, preventing reliable monitoring of that output current.

Common causes

Most likely first.

1. Signal wire shorted to ground
2. Internal sensor short
3. Connector pins corroded - high contact resistance

Symptoms

• Charge status indicator shows fault
• Charging may not start or interrupts
• Slower-than-expected charge rate

How to diagnose it

1. Check freeze-frame and live output current sensor data to confirm the low signal and identify when it occurs.
2. Inspect the sensor connector and signal wiring for corrosion, loose pins, damage, or contact with ground.
3. Check the sensor supply, ground, and signal connections against the wiring diagram and manufacturer's specification.
4. Test the signal wire for a short to ground and check for an internal sensor short using the manufacturer's procedure.
5. If the circuit checks out, test the 14-volt output current sensor and replace it only if its signal remains below specification.

Common fixes

• Clean corroded connector pins and secure the output current sensor connection.
• Repair a signal wire shorted to ground or an open caused by damaged wiring.
• Replace a shorted or failed 14-volt output current sensor.

Can I keep driving?

Charging may fail to start, be interrupted, or run slowly, and the vehicle may limit charging functions. Do not rely on normal charging until the low current-sensor signal is repaired.