Powertrain, generic

P0E37 DC/DC Converter Voltage Sensor B Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P0E37 says that voltage sensor B delivers a believable number which nevertheless disagrees with what the vehicle measures elsewhere. GM's 2025 engine tables (25OBDG03A) check raw voltage value 2 of the converter against the ECM run/crank voltage: in bypass mode a gap above 2 V counts, and 320 failed samples out of 400 at 12.5 ms set a Type B code. During an automatic engine restart the converter stabilises the 12 V supply, and then 8 of 16 samples are enough. FCA, which calls this channel voltage sensor 2, changed the code from a two-trip to a one-trip code with flash 08-037-21 for the 2021 Ram 1500 eTorque. Drift in the measurement, voltage drop on wiring or outdated software are typical; hard shorts are P0E38 and P0E39.

Likely causes

Second voltage measurement in the converter drifting
Voltage drop on supply or ground wiring distorting the comparison
Controller software needing an update (FCA eTorque)

Symptoms

  • MIL on, after one or two trips depending on maker and software
  • Start-stop unavailable

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–1,500
Time0.5–3 h

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

Parts involved

dcdc voltage sensor bwiring harnessdcdc converter

Related codes

P0E32P0E36P0E38P0E39P0E3A

References: gsi.ext.gm.com, static.nhtsa.gov.