Powertrain, generic (extended)

P2849 Shift Fork A Stuck

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2849 says that fork A did not travel when the module ordered it to, so its gear could not be put in or taken out. The reading may be valid; the fork itself is not following the command. No manufacturer publishes a strategy for P2849, and the code relies on the CARB 13 CCR 1968.2 rule that transmission components be checked for proper function. GM's 2023 Corvette table shows how a frozen rod is found: an intrusive integrity routine nudges each rod in both directions through its synchronizer valves and expects more than 100 µm of travel. GM, however, charges a rod that never moves to its position sensor and logs it under the first rod's consistency code P2832. Causes range from a seized rod or broken fork to a failed actuator.

Likely causes

Fork A actuator or its control valve not moving the rod
Shift rod of fork A seized in its bore or blocked by debris
Broken fork or damaged synchronizer sleeve jamming the shift

Symptoms

  • Gear of fork A will not engage or stays engaged
  • Limp-home mode with limited gears
  • Clunking or grinding during shift attempts

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€300–4,500
Time2–12 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

shift fork ashift fork actuator asynchroniser assembly

Related codes

P284AP284BP284CP2869P2832

References: law.cornell.edu, gsi.ext.gm.com.