Powertrain, generic (extended)

P2DA7 Coolant Heater A Control Module System Voltage

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2DA7 is logged when the electronics built into coolant heater A – the HV heater of a hybrid or EV – see a system voltage outside the window in which it may work. While P2DA5 points to the feed circuit, this code judges the level. High-voltage heaters have a defined range; DBK's 400 V unit, for example, runs from 195 to 450 V DC, and Texas Instruments notes that heater controllers must cope with a varying DC bus and may monitor their supply rails. No manufacturer documents P2DA7 publicly or states whether it rates the HV or the 12 V side. Typical reasons are a strongly discharged or very full traction battery, a weak 12 V battery or a measuring fault in the heater. The heater stays off while the voltage is out of range and usually resumes afterwards.

Likely causes

Traction battery voltage at the edge of the heater's range (very low or very high charge)
Weak 12 V battery or poor ground of the heater electronics
Voltage measurement inside the heater faulty

Symptoms

  • Electric heater temporarily without function
  • Fault occurs with very low or very high battery charge
  • Cabin heat only from the engine of a hybrid

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–1,800
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

coolant heater acoolant heater a control module

Related codes

P2DA4P2DA5P2D9EU069E

References: en.dbk-group.com, ti.com.