Open or high-resistance wiring in the precharge contactor control circuit (e.g., broken wire, corroded connector); Faulty precharge contactor coil or internal contactor assembly; Failed battery energy control module (BECM) or hybrid control module driver; Poor ground connection for the contactor control circuit; Short to ground in the control circuit causing low voltage; Water intrusion or corrosion in the battery pack connector; Aftermarket accessories improperly tapped into the control circuit

DTC codes / P0Exx · Hybrid propulsion / P0E6B

P0E6BHybrid/EV Battery Precharge Contactor Control Circuit Low

Q: What does code P0E6B mean?

Hybrid/EV Battery Precharge Contactor Control Circuit Low. P0E6B indicates that the hybrid or electric vehicle battery precharge contactor control circuit has a low voltage condition, meaning the control module detected a voltage below the expected threshold on the circuit that commands the precharge contactor. The precharge contactor is a relay that limits inrush current when connecting the high-voltage battery to the rest of the system, and a low control circuit can prevent proper precharge or cause the contactor to remain open.

P0E6B indicates that the hybrid or electric vehicle battery precharge contactor control circuit has a low voltage condition, meaning the control module detected a voltage below the expected threshold on the circuit that commands the precharge contactor. The precharge contactor is a relay that limits inrush current when connecting the high-voltage battery to the rest of the system, and a low control circuit can prevent proper precharge or cause the contactor to remain open.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaHybrid propulsion

Symptoms you may notice

Illumination of the hybrid system warning light or service vehicle soon message
The vehicle may fail to enter 'Ready' mode or start
Reduced power or limp mode due to high-voltage system isolation
Audible clicking or no click from the battery pack area when attempting to start
Often no symptoms besides the warning light, especially if the fault is intermittent
Possible inability to charge the high-voltage battery in plug-in hybrids

Common causes, most likely first

Open or high-resistance wiring in the precharge contactor control circuit (e.g., broken wire, corroded connector)
Faulty precharge contactor coil or internal contactor assembly
Failed battery energy control module (BECM) or hybrid control module driver
Poor ground connection for the contactor control circuit
Short to ground in the control circuit causing low voltage
Water intrusion or corrosion in the battery pack connector
Aftermarket accessories improperly tapped into the control circuit

How to diagnose and fix it

Perform a visual inspection of the precharge contactor circuit wiring and connectors for damage or corrosion
Check for technical service bulletins (TSBs) or recalls related to the hybrid battery contactor circuit
Measure resistance and voltage on the control circuit at the contactor and at the control module to identify opens or shorts
Test the precharge contactor coil for continuity and compare to specification
Verify ground integrity for the control circuit using a voltage drop test
If the circuit is intact, substitute a known-good contactor or control module to isolate the fault
Clear codes and perform a road test to confirm the repair, ensuring the hybrid system operates normally

Before you replace the hybrid battery pack

A low control circuit code often results from a simple wiring issue, such as a chafed wire or loose connector, rather than a failed contactor or battery pack.
The precharge contactor is sometimes part of the battery pack assembly and may not be serviceable separately, but the control circuit can still be tested independently.
Intermittent faults may only set the code under specific conditions like cold starts or high humidity, so a wiggle test of the harness while monitoring live data can be revealing.
Do not overlook the ground connection for the control module; a poor ground can cause a low voltage code on multiple circuits.
Replacing the battery pack without testing the control circuit first is an expensive misdiagnosis that technicians commonly encounter.

Can I keep driving with P0E6B?

If the warning light is on and the vehicle still drives, limit driving to essential trips and avoid high-voltage system stress such as rapid acceleration or heavy loads. If the vehicle fails to start or enter Ready mode, do not continue driving; have it towed to a qualified hybrid service facility.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.