OBDII Code List

P1AA9 CADILLAC - Starter/Generator Phase U Current Sensor Performance

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3   
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Possible causes

  • Faulty Starter/Generator Control Module (SGCM)
  • Starter/Generator Control Module (SGCM) harness is open or shorted
  • Starter/Generator Control Module (SGCM) circuit poor electrical connection

Possible symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P1aa9 Cadillac Description

The Starter/Generator Control Module (SGCM) unit is an electronic device that works in conjunction with the electrical subsystem to efficiently perform DC/DC and DC/AC electrical energy conversion and support vehicle functions.

This SGCM will have 2 functions. The first will be monitoring, where the DC voltage is transformed into three phase A/C power to the Starter Generator interface. In this case, energy flows from battery 36-volt to Phase 1, Phase 2, Phase 3. The second case will be generating, where the three phase AC power is used to charge the 36 V battery pack. In this case, energy flows from Phase 1, Phase 2, Phase 3 to battery 36-volt. If the values of Starter Generator Speed and Starter Generator Torque are zero, then the Starter Generator Control will be disabled and the Starter Generator Inverter is not transferring or consuming any power.

OBDII Code P1aa9 Cadillac - Starter/Generator Phase U Current Sensor Performance -

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