P1A98

DTC P1A97 or P1A98

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 P1A97
- Starter/Generator Control Module Hybrid Battery Voltage Sense Circuit Low Voltage

DTC P1A98
- Starter/Generator Control Module Hybrid Battery Voltage Sense Circuit High Voltage




Circuit/System Description

The starter/generator control module (SGCM) monitors the hybrid battery voltage sense circuit low and circuit high to detect the failure of the 36-volt output voltage sensor circuit below or above a valid range.


Conditions for Running the DTC

P1A97, P1A98

The engine is running.


Conditions for Setting the DTC


P1A97
* Sensor signal is less than 0.2 volt for continuous 20 ms.
* Sensor signal is less than 0.2 volt for 20 ms and 36-volt battery voltage is greater than 5 volts for 20 ms.


P1A98

Sensor output voltage less than 4 volts and 36-volt battery voltage is greater than 5 volts for 20 ms.


Action Taken When the DTC Sets


P1A97, P1A98
* Stop PWM (MGU shutdown).
* APM PWM off.



Conditions for Clearing the DTC

P1A97, P1A98

Closes 30 seconds after cycle wake up signal.


Diagnostic Aids

P1A97

Possible sensor short to ground.

P1A98

Possible short to voltage or open.


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.


P1A97, P1A98

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