Powertrain, generic · Hybrid propulsion

P0A89 14 Volt Power Module Current Sensor A Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P0A89 is set when the current sensor of the 14 V power module reports more current than the converter can physically carry. GM's eAssist tables show how: in 2013 the APM input current reading had to exceed 22.5 A for 1.5 s while calculated output power was 1.5 kW or less; in 2016 the limit is 45.25 A or more in 200 of 250 samples (about 5 s) with the APM commanded on and 9 to 32 V supply. Both versions classify it Type B, so the MIL lights after the second failing trip. Typical causes are a signal short to voltage or an internal sensor fault. P0A88 is the low counterpart, P0A87 the in-range plausibility test, and the APM output sensor has its own codes (P0C9E/P0C9F).

Likely causes

Sensor signal shorted to supply voltage
Current sensor in the power module failed
Open sensor ground pulling the signal high

Symptoms

  • MIL and hybrid/charging warning
  • Converter output limited, 12 V voltage drops
  • Start/stop function may be disabled

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–1,800
Time1–4 h

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

Parts involved

pm14v current sensor awiring harnessdcdc converter

Related codes

P0A86P0A87P0A88P0A8AP0C9F

References: gsi.ext.gm.com, gsi.ext.gm.com.