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DTC codes / P2Exx · Hybrid propulsion / P2E38

P2E38Battery Charger B Enable Circuit Range/Performance

P2E38 indicates that the powertrain control module (PCM) has detected an out-of-range or performance fault in the enable circuit for battery charger B, which is typically a secondary high-voltage charging path on electrified vehicles. The PCM monitors the circuit's voltage or current feedback and sets this code when the signal does not match the expected profile during enable or operation.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaHybrid propulsion

Symptoms you may notice

  • Illumination of the check engine light or service vehicle soon message
  • Often no symptoms besides the warning light, especially if the main charging system still works
  • Reduced or absent charging from the auxiliary battery charger, leading to a low 12-volt battery over time
  • Possible electrical accessories dimming or behaving erratically
  • In some cases, a no-start condition if the auxiliary battery is not maintained

Common causes, most likely first

  1. Faulty battery charger B enable relay or solid-state switch
  2. Open or shorted wiring in the enable circuit, including chafed harnesses or corroded connectors
  3. Failed battery charger B unit itself, such as internal driver or feedback circuit failure
  4. PCM software issue or internal driver fault on the enable output
  5. Poor ground connection for the charger or enable circuit
  6. Blown fuse or fusible link protecting the enable circuit

How to diagnose and fix it

  1. Verify battery voltage and state of charge, then clear the code and test-drive to confirm it returns
  2. Inspect the enable circuit fuse and replace if blown, checking for the cause of the overload
  3. Visually inspect the charger B enable circuit wiring and connectors for damage, corrosion, or loose pins
  4. Measure resistance and voltage drop on the enable circuit from the PCM to the charger, comparing to specifications
  5. Command the charger B enable circuit on with a scan tool and verify voltage or current at the charger
  6. If the circuit is intact, substitute a known-good charger B unit or relay to test operation
  7. Check for PCM software updates and reflash if applicable, or diagnose the PCM driver if all else fails

When the charger enable circuit looks fine

  • A common oversight is assuming the charger itself is faulty when the enable circuit is actually being commanded off by the PCM due to a separate charging system fault or low 12-volt supply.
  • The enable circuit often shares a ground with other high-current components, so a corroded ground can cause this code without any visible damage to the charger wiring.
  • On some vehicles, battery charger B is only active during specific conditions such as low state of charge or high electrical load, so the code may not set during a short test drive.
  • A scan tool that can read live data for the charger enable status is more useful than a simple code reader, because it shows whether the PCM is actually commanding the circuit on.
  • Aftermarket accessories wired into the charging system can backfeed the enable circuit and trigger this code, so always check for non-factory wiring before replacing parts.

Can I keep driving with P2E38?

You can usually continue driving if the only sign is the warning light and the vehicle starts and runs normally, but avoid long trips or heavy electrical loads until the fault is repaired. If the battery voltage gauge shows low voltage or the vehicle struggles to start, stop driving and charge or replace the auxiliary battery before proceeding.

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.

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