P1A70

DTC P1A70

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 Descriptor
DTC P1A70
- Starter/Generator Control Module System Voltage Performance




Circuit/System Description

The starter/generator control module (SGCM) monitors the performance to detect 12-volt DC wire electrical failure by comparing the 12-volt input to the 12-volt output values. If the difference is greater than 5 volts, the DTC sets.


Conditions for Running the DTC

* The engine is running.
* Hybrid mode is active.



Conditions for Setting the DTC

The 12-volt power supply - 12-volt output voltage is greater than 5 volts for 119 ms and any fault during 15 seconds wait period.


Action Taken When the DTC Sets

* Stop PWM (MGU shutdown).
* APM PWM off.



Conditions for Clearing the DTC

Cycle wake up signal.


Diagnostic Aids

Possible 12-volt battery or APM voltage sensor stuck.


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