P2E85: Battery Charger B Input Voltage Sensor Circuit Low

What it means

The input voltage sensor of battery charger B reports a low fault. Mains input voltage measurement is unreliable.

At a glance

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

How it works

Battery charger B uses its input-voltage sensor to measure mains power at the charging inlet. The control module monitors the sensor signal; this code sets when that signal is below its expected range, which can result from a short to ground, an internally shorted sensor, or poor connector contact.

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. Review freeze-frame data and read live input-voltage sensor B data while the charger is connected.
2. Check whether the charge status indicator shows a fault and whether charging fails or interrupts as the reading stays low.
3. Inspect charger B's sensor connector for corrosion, contamination, loose pins, or damaged terminals.
4. With the correct wiring information, check the signal wire for a short to ground and inspect the connector for excessive contact resistance.
5. If the wiring and contacts are sound, test sensor B and compare its output with the manufacturer's specification.

Common fixes

• Clean and reconnect the sensor B connector if dirty or loose.
• Repair corroded or damaged connector pins causing high contact resistance.
• Repair a signal wire shorted to ground.
• Replace the input-voltage sensor or charger B module if testing confirms an internal short.

Can I keep driving?

Driving is generally possible, but charger B may refuse to charge or interrupt charging, leaving the battery below its intended level. Arrange another reliable way to charge the vehicle until the fault is repaired.