PIT5868B
Service Bulletin Details
Public Details for: PIT5868B
This preliminary information communicates an issues will low or poor heater performance on the drivers side. Dealers are to inspect the hvac temperature door linkage and if ok replace the heater core.
Models from 2022
Models from 2021
Models from 2020
| 2020 CHEVROLET SILVERADO 1500 |
| 2020 CHEVROLET SILVERADO 2500 |
| 2020 CHEVROLET SILVERADO 3500 |
| 2020 GMC SIERRA 1500 |
| 2020 GMC SIERRA 2500 |
| 2020 GMC SIERRA 3500 |
Models from 2019
| 2019 CHEVROLET SILVERADO 1500 |
| 2019 GMC SIERRA 1500 |
Bulletin No.: PIT5868B Published date: 01/17/2023 Preliminary Information PIT5868B Poor Heater Performance On Drivers Side Models Brand: Model: Model Years: VIN: from to Engine: Transmissions: Cadillac Escalade Models 2021 - 2022 All All All All Chevrolet Silverado 1500 (New Model) 2019 All All All All Chevrolet Silverado 2020 - 2022 All All All All Chevrolet Suburban 2021 - 2022 All All All All Chevrolet Tahoe 2021 - 2022 All All All All GMC Sierra 1500 (New Model) 2019 All All All All GMC Sierra 2020 - 2022 All All All All GMC Yukon Models 2021 - 2022 All All All All Involved Region or Country North America Condition Some customers may comment on lower heater performance from the driver side HVAC vents when compared to the passenger side. In some cases, the driver side center dash vent will have the lowest temperature. The cause of this condition could be one of the following: Cause 1: The heater core may have become plugged. When the heater core begins to plug, it a ects the driver side center vent rst. Cause Cause 2: Both single and dual zone HVAC cases utilize two temperature doors per side (a total of four doors), shown below. In the photo below, call-out 1 shows the passenger side temperature doors and heater core. Call-out 2 show the driver side temperature doors and heater core. Call-out 4 shows the evaporator air temperature sensor location in relation to the driver side temperature door which will be helpful later in this document. Inside the HVAC case, there are four white links which connect each of the four temperature doors. In some cases, one of these white links can become disconnected inside the HVAC case, as shown below (3). Correction: If, after performing normal SI diagnostics, the cause has been determined to be an issue within the HVAC case, then perform the following: 1. Remove the Evaporator Air Temperature (EAT) sensor (4) from the HVAC case, as shown below. Next, using a bore scope through the opening for the EAT sensor (5), inspect both driver side temperature doors while changing the HVAC temperature setting from full cold to full hot, or while manually rotating the driver side temperature door shaft with the temperature actuator removed. See rst photo above for the relationship between the driver temp doors and EAT opening (4). - If the temperature doors are moving through their full travel, then continue to Step 2. - If a temperature door is not moving, or not moving properly, then this could be an issue with a white link disconnected, temperature door issue, or an actuator issue. Perform normal diagnostics to determine the root case. It may be necessary to disassemble the HVAC case to determine the root cause of a door issue and then replace any parts that are necessary. 2. If the driver side temperature doors are moving through their full travel then replace the heater core. Warranty Information The correction for this concern may be one of several repairs described above. For vehicles repaired under warranty, please use the appropriate warranty labor operation based on the actual cause and repair. Additional SI Keywords cold, cool, heat, hot, Version History Version 3 Modi ed 11/29/2021 - Created on. 02/24/2022 - Updates to the correction section 01/17/2023 - Update to the models © 2023 General Motors. All Rights Reserved.