Latent Fault Mode

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

When a fault is detected in the Electronic Transmission Range Selector system or the electronic parking brake, the data information center will display the message "Service Transmission Now, Unable to Shift Soon" along with a 10 second chime. The driver must acknowledge the message to show other data on the data information center. The frequency that the message and chime occur will increase until a programmed number of trips (50 or 100) are reached with the fault present. At that point, the transmission will not be allowed to shift out of park and the data information center will display the message "Service Transmission, Unable to Shift." Once fault is corrected and DTCs cleared, message should go away.

When "Service Shifter See Owner's Manual" message is shown on the data information center, the shift lever is requiring service. If the vehicle is automatically shifting into P (Park), check to see if the park button is stuck by running through the shifter electrical diagnostics. To operate the vehicle, hold the shift lever in the desired gear, R (Reverse) or D (Drive), until vehicle speed exceeds 15 km/h (10 mph), then release the shift lever.