A number of fuel-related DTCs may be set on some 2017-2018 Silverado, Sierra; 2019-2021 Silverado 2500HD/3500HD, Sierra 2500HD/3500HD, and Silverado 4500HD/5500HD/6500HD models equipped with the 6.6L Duramax diesel engine (RPO L5P, L5D). DTCs set in the Engine Control Module (ECM) may include P0087, P0089, P0191, P026C, P026D, P1089, P163A, P163B, P2293, P228A, P228B, P228C, and/or P228D. The Check Engine MIL also may be illuminated.
These conditions may be caused by corrosion or damage at the fuel pressure sensor electrical connector. (Fig. 30) Inspect the connector for any damage. It may be necessary to use the terminal test kit with dielectric grease on it to drag each terminal a few times.
Fig. 30
If a terminal is suspect, remove the terminal and inspect for any corrosion, damage or signs of the dielectric grease starting to turn black. (Fig. 31)
If any of these conditions are found, replace the electrical connector.
Fig. 31
Refer to Bulletin #20-NA-197 for additional information and part numbers.
– Thanks to Larry Yaw
Have had a couple of these where the corrosion is on the sensor terminals, was not replaced, but needed it within a couple of weeks. Also have had a couple where other fuel system problems were the root cause.
IF THE CONNECTOR IS FOUND TO BE AS BAD AS DEPICTED IN THE PHOTO , THEN WHY IS THE SENSOR NOT REQUIRING REPLACEMENT ACCORDING TO THE BULLETIN.