P0AE0: Hybrid/EV Battery Negative Contactor Control Circuit High

P0AE0 is stored when the negative contactor drive circuit shows too high a voltage for its state, which mostly means a short to battery voltage. GM's 2016-19 hybrid tables set it with the contactor commanded off and the driver output between 5.27 and 19.7 V for 40 of 50 samples at 12.5 ms, Type B, two trips. CARB 1968.2 requires hybrid output components to be monitored for such circuit faults. Siblings are P0ADD (open) and P0ADF (low); the positive side equivalent is P0ADC. A coil energized by a short could keep the contactor closed, so a stuck-closed code P0AA4 may follow. The controller usually disables the high-voltage system.

Symptoms

• Hybrid or EV warning light
• High-voltage system disabled, vehicle not ready
• Possible additional stuck-closed code

Most likely causes

• Coil control wire shorted to 12 V
• Damaged harness or connector at the battery disconnect unit
• Driver stage in the battery controller shorted

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes with a hybrid-compatible scanner and write down the freeze frame data
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Make sure the battery cooling air intake is clean
4. Check the 12 V auxiliary battery, which can also trigger warnings
5. Leave any high-voltage measurements to a specialized repair shop

Good to know

• It can trigger limp mode.
• It affects emissions.

What each character of P0AE0 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• A: Hybrid or air and fuel
• E0: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0AE0?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0AE0?

The most common causes are: coil control wire shorted to 12 V; damaged harness or connector at the battery disconnect unit; driver stage in the battery controller shorted.

Related codes

• P0ADDHybrid/EV Battery Negative Contactor Control Circuit/Open
• P0ADEHybrid/EV Battery Negative Contactor Control Circuit Range/Performance
• P0ADFHybrid/EV Battery Negative Contactor Control Circuit Low
• P0ADCHybrid/EV Battery Positive Contactor Control Circuit High
• P0AA4Hybrid/EV Battery Negative Contactor Circuit Stuck Closed

Sources

• gsi.ext.gm.com: 16OBDG02 Hybrid Diagnostics
• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.