DTC P1AB1. Chevrolet Malibu 2009

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2009 🢒 Malibu 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P1AB1

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P1AB1: Starter/Generator Phase U-V-W Current Sensor Overcurrent

Circuit/System Description

The starter/generator control module (SGCM) monitors the phase U/V/W current sensor to detect 3 phase overcurrent and to protect the MOSFET.

Conditions for Running the DTC

•	Engine is running.

•	Wake up signal is ON.

Conditions for Setting the DTC

Over current signal set for 20 ms.

Action Taken When the DTC Sets

•	Stop PWM (MGU shutdown)

•	APM PWM OFF

•	Battery disconnection (disconnect SW on/off)

Conditions for Clearing the DTC

Over current signal not valid

Diagnostic Aids

•	Possible MGU winding short to other winding or short to case

•	Possible FET breakdown or gate driver circuit fault

Reference Information

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

Disconnect the 3-phase cables from the SGCM. Refer to Generator Control Module 3-Phase Cable Assembly Replacement.
Test each of the 3-phase cables individually for a short to ground.

⇒	If any circuit indicates a short to ground , disconnect the 3-phase cables from the MGU.

⇒	If the short to ground condition is longer present, replace the MGU.

Test each of the 3-phase cables individually for a short to ground.

⇒	If any circuit does not test normal, replace the 3-phase cable assembly.

If all circuits test normal, replace the SGCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Generator Control Module 3-Phase Cable Assembly Replacement

•	Generator with Starter Replacement

•	Control Module References for SGCM replacement, setup, and programming