GM Bulletin # 24-NA-070 Revised: Start/Stop No-Restart Now Includes P1098 and Coolant Flow Control Valve Replacement
- Greg Nelson
- 2 days ago
- 3 min read
Greg Nelson - January 6, 2026
General Motors has issued a significant revision to Bulletin # 24-NA-070, expanding both the diagnostic scope and the approved correction path for certain 3.0 Duramax diesel vehicles experiencing no-restart events during Auto Stop/Start operation.
While the original bulletin focused primarily on DTC P138C and ECM software updates, the January 6, 2026 revision formally adds DTC P1098, introduces an Engine Coolant Flow Control Valve replacement procedure, and includes explicit warranty guidance.
These updates provide clearer direction for both diagnosis and repair when this condition is present.
Vehicles and Engines Affected LM2 Only
Models
Chevrolet Silverado 1500 (Limited and New)
GMC Sierra 1500 (Limited and New)
Chevrolet Tahoe
Chevrolet Suburban
GMC Yukon (All variants)
Cadillac Escalade (All variants)
Model Years
2021–2024
Select 2022 Limited / New body-style models as listed in the bulletin
Engine
3.0 L Duramax Diesel (LM2)
Markets : North America, Europe, Middle East, South America, Asia, and select global regions.
Although the bulletin notes a higher occurrence in California and in vehicles using renewable diesel, the condition and repair procedure are not limited to those locations or fuel types.
Reported Condition
Some customers may comment on one or more of the following:
Vehicle does not restart after coming to a stop while Auto Stop/Start is active
Malfunction Indicator Lamp (MIL) illuminated
Technicians may find one or more of the following DTCs stored in the ECM:
P138C
P1098
The inclusion of P1098 is new with the January 2026 revision.
GM-Identified Cause
According to the bulletin:
“This condition may be caused by a software anomaly.”
While the cause statement remains unchanged, the revised correction procedure now recognizes scenarios where additional hardware replacement is required when specific DTC criteria are present.
What Changed in the January 6, 2026 Revision
GM explicitly notes the following additions:
• P1098 Added
DTC P1098 is now included in the Subject, Condition, and Correction sections, formally linking it to the no-restart condition.
• Engine Coolant Flow Control Valve Replacement Added
If P1098 is set, the bulletin now instructs technicians to replace the Engine Coolant Flow Control Valve in addition to performing an ECM update.
• Warranty Information Added
Warranty guidance has been expanded to include:
ECM reprogramming
Coolant Flow Control Valve replacement
Warranty Claim Code (WCC) documentation requirements
Correction Summary
GM’s current correction path is as follows:
Check for active ECM campaigns
If a campaign is available, perform the update per campaign instructions
If no campaign is present, update the ECM to the latest available software
If DTC P1098 is set
Update the ECM
Replace the Engine Coolant Flow Control Valve
Clear DTCs after programming and repairs are complete
Engine Coolant Flow Control Valve
The addition of this component to the repair procedure indicates GM has identified cases where the thermal management system contributes to the no-restart condition when paired with certain DTCs.
Parts Information
Description | Part Number | Quantity |
Valve Assembly – Engine Coolant Flow Control | 40009644 | 1 |
Programming and Service Notes (Summary)
GM emphasizes the following during ECM programming:
Use a hard-wired internet connection only
Maintain stable battery voltage with an approved programming support tool
Do not use a battery charger during programming
Verify the VIN matches the vehicle before programming
Record the Warranty Claim Code (WCC) to avoid claim rejection
Failure to follow these steps may result in programming failure or warranty issues.
Why This Revision Matters
This update expands the bulletin beyond a software-only correction and provides a defined repair path when P1098 is present. It also clarifies warranty handling and confirms that certain no-restart conditions may involve both calibration and hardware correction.
For owners who previously experienced repeat concerns after ECM updates alone, this revision establishes additional diagnostic and repair guidance.
Summary
The January 6, 2026 revision of GM Bulletin # 24-NA-070 adds meaningful clarification by:
Formally linking P1098 to the no-restart condition
Introducing Engine Coolant Flow Control Valve replacement when required
Expanding warranty guidance to support the updated repair procedure
While the bulletin continues to identify software as the underlying cause, GM now recognizes that specific conditions require additional corrective steps to fully resolve the concern.