OBD Guide

P2E78

Hybrid/EV Battery Pack Coolant Temperature Sensor D Circuit Intermittent/Erratic

P2E78 is an OBD-II diagnostic trouble code meaning: Hybrid/EV Battery Pack Coolant Temperature Sensor D Circuit Intermittent/Erratic. Common causes: poor contact in the sensor connector, wiring harness damage. Estimated repair cost: $17–56.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Unstable battery coolant temperature readings
  • Reduced performance of the hybrid system
  • Check Engine Light Illuminated
  • Possible reduction in vehicle power
  • Activation of emergency operation

Causes

  • Poor contact in the sensor connector
  • Wiring harness damage
  • Temperature sensor malfunction
  • Corrosion of electrical contacts
  • Problems with the battery control unit

How to Fix

  1. Check connections and sensor connector
  2. Inspect the wiring harness for damage
  3. Test the temperature sensor
  4. Clean contacts from corrosion
  5. Replace sensor if necessary

Related codes

Error P2E78 by Vehicle Brand

FAQ

What does the P2E78 code mean?

P2E78 is an OBD-II diagnostic trouble code that indicates: Hybrid/EV Battery Pack Coolant Temperature Sensor D Circuit Intermittent/Erratic

What causes a P2E78 error code?

The most common causes of P2E78 include: Poor contact in the sensor connector; Wiring harness damage; Temperature sensor malfunction; Corrosion of electrical contacts.

How do I fix a P2E78 diagnostic trouble code?

To fix P2E78: Check connections and sensor connector. Inspect the wiring harness for damage. Test the temperature sensor. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P2E78?

Yes, but get it checked soon

How much does it cost to fix P2E78?

The estimated repair cost for P2E78 is $17–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat