Powertrain, generic

P0E20 Hybrid/EV Battery Pack Coolant Control Valve A Control Circuit Driver Current/Temperature Too High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0E20 points at the driver that powers coolant control valve A: its output has exceeded a current limit or run too hot and switched itself off. No manufacturer documents P0E20 publicly. Valve A is often a small motor actuator; on the 2011 Chevrolet Volt it is driven in both directions through two drive lines, each with its own ground and voltage short checks (90 failures in 100 samples at 6.25 ms, Type B). Driving a motor into a jammed end stop is exactly what heats such a stage, so a sticking valve is a prime suspect. Mercedes reports the electrical fault of its battery shutoff valve as P0CDF00 instead. TI's automotive smart switches illustrate the protection itself: shut-off at the current limit or near 150 °C, with a fault flag. P0E21 and P0E22 cover valves B and C.

Likely causes

Valve A sticking or jammed so the actuator stalls
Partial short in the valve actuator motor or its wiring
Degraded valve driver in the control module

Symptoms

  • Check engine light on
  • Valve A stays in its last position
  • Battery runs too warm or too cold, power or charging limited

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–900
Time0.5–3 h

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

Parts involved

hv battery pack coolant valve abms

Related codes

P0E21P0E22P0CDFP0CE2P0CE3U0636

References: gsi.ext.gm.com, static.nhtsa.gov, ti.com, law.cornell.edu.