CEL showed up with error code P0844
Thread Starter
22 Hypersonic Grey HTC
Joined: Mar 2014
Posts: 506
Likes: 144
From: Austin Texas
CEL showed up with error code P0844
P0844 - Transmission Fluid Pressure Sensor/Switch "A" Circuit Intermittent
Anyone have this error code show up with a CEL? If so, what did you do to resolve it?
I have about 2,100 miles on my 2021 and got this code today.
Anyone have this error code show up with a CEL? If so, what did you do to resolve it?
I have about 2,100 miles on my 2021 and got this code today.
Thread Starter
22 Hypersonic Grey HTC
Joined: Mar 2014
Posts: 506
Likes: 144
From: Austin Texas
From what I'm reading, I'll be scheduling an appointment at the dealer for the transmission system cleaning for DTC P0844 that showed up this weekend just past 2,000 miles on the odometer.
I searched the latest GM Techlink and found this in the February 2021 issue:
If DTCs: P0844, P0841, P0849, P0846, P0874, P0871, P0879 and/ or P0876 are set: • Perform the system cleaning procedure based on the DTC that set. • Next, perform the Service Clean Procedure and then Service Fast Learn. • If no other pressure DTCs are present, proceed to circuit diagnostics.
SERVICE PROCEDURES After recording and clearing the DTCs, and with the transmission at operating temperature, use GDS2 to perform the transmission system cleaning procedures. Select the transmission cleaning services that correspond with the DTCs set. Not all cleaning procedures listed need to be performed. For more details about each cleaning procedure, refer to SI document #5501008 – K71 Transmission Control Module: Scan Tool Information. Perform the DTC solenoid cleaning procedure three times for each DTC set. Once the cleaning procedure has been completed three times, select the Configurations/Reset Functions in order to perform the Transmission Service Fast Learn procedure as needed. Be sure to test drive the vehicle after performing the cleaning procedures to verify that the DTCs do not reset. If the DTCs reset, replace the Control Valve Solenoid (or Main Control Valve, MCV). For additional information, refer to Bulletin #21-NA- 033.
I searched the latest GM Techlink and found this in the February 2021 issue:
If DTCs: P0844, P0841, P0849, P0846, P0874, P0871, P0879 and/ or P0876 are set: • Perform the system cleaning procedure based on the DTC that set. • Next, perform the Service Clean Procedure and then Service Fast Learn. • If no other pressure DTCs are present, proceed to circuit diagnostics.
SERVICE PROCEDURES After recording and clearing the DTCs, and with the transmission at operating temperature, use GDS2 to perform the transmission system cleaning procedures. Select the transmission cleaning services that correspond with the DTCs set. Not all cleaning procedures listed need to be performed. For more details about each cleaning procedure, refer to SI document #5501008 – K71 Transmission Control Module: Scan Tool Information. Perform the DTC solenoid cleaning procedure three times for each DTC set. Once the cleaning procedure has been completed three times, select the Configurations/Reset Functions in order to perform the Transmission Service Fast Learn procedure as needed. Be sure to test drive the vehicle after performing the cleaning procedures to verify that the DTCs do not reset. If the DTCs reset, replace the Control Valve Solenoid (or Main Control Valve, MCV). For additional information, refer to Bulletin #21-NA- 033.
