P2E8E: Battery Charger B Charge Sequence Signal 2 Circuit High

What it means

The charge sequence signal 2 circuit of battery charger B reports voltage above the expected window. Charging handshake compromised.

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 charge-sequence signal 2 as a separate part of its charging handshake. The control module sets this code when signal 2 rises above its expected range, which can stop the handshake from completing even if signal 1 is functioning.

Common causes

Most likely first.

1. Signal wire shorted to B+
2. Pull-down resistor open
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 charger-related codes and freeze-frame data, noting whether the charging fault is associated with charger B.
2. Inspect the signal 2 connector pins and harness for corrosion, looseness, water intrusion, or damage.
3. With the system safely isolated according to the vehicle procedure, test signal 2 for a short to battery positive.
4. Measure signal 2 at the relevant connector and compare it with the manufacturer's specification to verify the high reading.
5. If wiring and terminals are sound, test the signal 2 pull-down path and charger B input according to the manufacturer's diagnostic procedure.

Common fixes

• Clean or repair corroded signal 2 connector contacts.
• Repair a signal 2 wire shorted to battery positive.
• Repair an open or failed signal 2 pull-down path if confirmed by testing.
• Repair or replace charger B only if its signal 2 input is faulty with a sound circuit.

Can I keep driving?

The high signal can prevent charging from starting, interrupt it, or leave the charge rate lower than expected. Do not count on charger B for a necessary charge until the fault is corrected.