P27B1

Internal Control Module Transmission Range Select Performance

Severity

🔴 High

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$56–278 (est.)

Symptoms

Incorrect gear shifting
Check Engine Light Illuminates
Transmission transition to emergency mode
Difficulty shifting gears
Power Loss

Causes

Transmission control module malfunction
Wiring Harness Problems
Selector lever position sensor malfunction
Mechanical damage in the switching system
Outdated ECU software

How to Fix

Check error codes in the ECU memory
Inspect the wiring harness and module connectors
Check the gear selector position sensor
Update ECU software
If necessary, replace the control module

Related codes

P27B0 P27B2 P27B3