Powertrain, generic (extended)

P2D96 Starter/Generator Phase Y Current Sensor Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2D96 covers the phase Y current sensor of the starter/generator when its signal drops below the valid range, for instance through a short to ground or a missing sensor supply. For the driver the more important part is how the controller reacts: without a trustworthy phase current it will usually limit or stop electric assist, stop-start can be suspended and charging through the machine may fall back, with a warning lamp. In GM's eAssist analogue the switch to sensorless current control happens within about 0.19 s, and the code is stored as Type B over two trips. No manufacturer documents P2D96 publicly. Check sensor supply and ground at the machine first. P2D93 is the high fault of Y; the series goes on with P2D97 for phase Z low, and P2D99 is the intermittent Y fault.

Likely causes

Phase Y sensor signal pulled to ground by damaged insulation
Open circuit in the sensor supply or a backed-out terminal
Phase Y current sensor defective

Symptoms

  • Electric assist reduced or switched off
  • Stop-start suspended
  • Battery or system warning, charging may be reduced

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–2,000
Time0.5–4 h

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

Parts involved

starter generator phase y current sensorwiring harnessstarter generator control module

Related codes

P2D93P2D95P2D97P2DC3P2DC4P2D99

References: gsi.ext.gm.com, law.cornell.edu.