GM Announces Diagnostic Time Allowance Changes

As a result of technician feedback, GM is implementing a new Diagnostic Time Strategy. This new process is designed to provide adequate time for technicians to diagnose the most difficult conditions. (Fig. 11)

Fig. 11

Increase in Diagnostic Time

Beginning July 1, diagnostic time changed from a flat 0.3 to a variable 0.1–1.0 time on over 1,100 labor operations. The increase was applied to labor operations that traditionally have had the highest amount and percentage of Other Labor Hours (OLH), such as electrical and module diagnosis. Other operations also have been reviewed. For example, the labor time for evacuation and recharge of the R1234YF air conditioning system has been increased from 0.5 hours to 1.2 hours.

In addition, diagnostic time was removed on 93 labor operations that are easy to identify, such as those involving trim and light bulb replacement. If additional labor time is needed on these items, the current OLH process should be followed.


Claim Submissions

Variable diagnostic time of 0.1–1.0 can be submitted in the Diagnosis Time field instead of the 0.3 time. (Fig. 12) Technicians are required to punch on and punch off for all diagnostic time. As always, diagnostic time must include supporting documentation, including proper cause and correction comments.

Fig. 12

Labor operations aside from modules not in the following categories remain at 0.3:

54 – Power and Signal

40 – Engine Propulsion

34 – Driver Information and Entertainment

20 – Body Systems

84 – Transmission

64 – Safety and Security

50 – Hybrid

Any additional time needed for operations that did not have an increase applied should follow the current OLH process. U.S. dealerships can self-authorize up to 0.5 hours of OLH. Potentially, a claim submission could be approved without review with up to 1.5 hours of diagnostic time, including the OLH.

For additional information about diagnostic time and OLH submissions, refer to Bulletin #18-NA-263.


Labor Time Guide

The Labor Time Guide (LTG) will reflect these new changes. There will be two new add times in the LTG — one for U.S./Canada indicating 0.1–1.0 and another that excludes U.S./Canada and reflects the current 0.3 for other Regions/Countries. (Fig. 13)

Fig. 13

The benefits to the new Diagnostic Time Strategy are expected to be many:

  • An increase in vehicles fixed right the first time
  • Increased customer satisfaction
  • Less repeat repairs
  • A reduction in excessive warranty part replacements.


– Thanks to Eric Kenar

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  1. Refer to warranty administration bulletin 18-NA-263 for additional information on Other Labor Hours (OLH) submissions.

  2. How has the process been changed on how a technician is to punch on and off repair orders in order to be compliant.