P1A26

DTC P1A26 or P1A27

Diagnostic Instructions

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

DTC Descriptor

DTC P1A26
- Hybrid Battery 1 Voltage Low

DTC P1A27
- Hybrid Battery 1 Voltage Very Low

Circuit/System Description

The engine control module (ECM) monitors the hybrid battery 1 voltage to detect if the minimum voltage is less than the calibration value.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

P1A26

Minimum module voltage is less than calibration value for 3 seconds.

P1A27

Minimum module voltage is less than calibration value for 40 ms.

Action Taken When the DTC Sets

The hybrid system is disabled.

Conditions for Clearing the DTC

P1A26, P1A27

System voltage 11 volts - 18-volts.

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.

Caution: To help avoid personal injury, be careful when working in the vicinity of the generator battery disconnect control module. Internal components will still be live, 36V potential, even when the cover has been opened or removed.

P1A26, P1A27
1. If DTC is history, refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids. Component Tests and General Diagnostics
2. If DTC is current, replace the BECM.

Repair Instructions

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

Control Module References for BECM replacement, setup, and programming.