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

Engine running or Ignition in ON position.

P1A26

Minimum module voltage is less than calibration value for 5 seconds.

P1A27

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

DTC sets, no action is taken.

Hybrid battery pack voltage returns above the expected minimum voltage range.

Schematic Reference

Hybrid Controls Schematics

Connector End View Reference

Hybrid Controls Connector End Views

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

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.

1. If other DTCs are set diagnose those first.
2. These DTCs are for information only. The DTCs can set in cold weather. Clear the DTC, no diagnostic or removal/replacement procedures are required.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.