P1AB4

DTC P1AB3-P1AB8

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.



DTC Descriptors
DTC P1AB3
- Starter/Generator Phase U Current Sensor Circuit Low Voltage

DTC P1AB4
- Starter/Generator Phase U Current Sensor Circuit High Voltage

DTC P1AB5
- Starter/Generator Phase V Current Sensor Circuit Low Voltage

DTC P1AB6
- Starter/Generator Phase V Current Sensor Circuit High Voltage

DTC P1AB7
- Starter/Generator Phase W Current Sensor Circuit Low Voltage

DTC P1AB8
- Starter/Generator Phase W Current Sensor Circuit High Voltage




Circuit/System Description

The starter/generator control module (SGCM) phase U/V/W current sensors are used for motor control and power inverter module (PIM) current sensor rationality check. The SGCM monitors the current sensor for the following:

* To detect a failure of the U/V/W-phase current sensor circuit below valid range
* To detect a failure of the U/V/W-phase current sensor circuit above valid range


If one of the above conditions is detected, the SGCM will set the appropriate DTC.


Conditions for Running the DTC


P1AB3, P1AB4, P1AB5, P1AB6, P1AB7, P1AB8
* Engine is running.
* Wakeup signal is ON.



Conditions for Setting the DTC

P1AB3, P1AB5, P1AB7

Sensor output voltage at high side less than 0.5 volt for 0.5 ms.

P1AB4, P1AB6, P1AB8

Sensor output voltage at high side greater than 4.5 volts for 0.5 ms.


Action Taken When the DTC Sets


P1AB3, P1AB4, P1AB5, P1AB6, P1AB7, P1AB8
* Stop PWM (MGU shutdown)
* APM PWM OFF
* Battery disconnection (disconnect SW on/off)



Conditions for Clearing the DTC

P1AB3, P1AB4

U-phase current sensor circuit within valid range

P1AB5, P1AB6

V-phase current sensor circuit within valid range

P1AB7, P1AB8

W-phase current sensor circuit within valid range


Diagnostic Aids

P1AB3, P1AB5, P1AB7

Possible Electrical failure at current sensor with short to ground or open

P1AB4, P1AB6, P1AB8

Possible electrical failure at current sensor with short to voltage


Reference Information
Schematic Reference

Hybrid Controls Schematics ()
Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)for Scan Tool Information


Circuit/System Verification

Caution: To help avoid personal injury, additional precautions must be taken prior to working on the generator control module or the generator starter. After removing the 36V battery cables from the generator battery, remove both engine wiring harness connectors from the generator control module. Wait at least 5 minutes and then remove the generator control module cover. Verify voltage levels at all 36V, 12V, and 3-phase connections, are less than 3 volts using a DMM before proceeding.


If DTC is current, replace the SGCM.


Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.


Control Module References (Programming and Relearning)for SGCM replacement, setup, and programming