Powertrain, generic · Transmission

P0829 5-6 Shift

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Shift codes check the gear change itself: the module compares the commanded change with the speed trace and flags a shift that takes too long, does not happen, flares or binds up two clutches. P0829 covers the change between 5th and 6th gear in either direction; J2012 placed it here because P0785 ff were already taken, between P0781 '1-2 Shift' to P0784 '4-5 Shift' and P07DA/P07DB for 6-7 and 7-8. No manufacturer document available to us uses it: Ford's Diesel summary checks shift completion without a gear-specific code (speed must drop by more than 30 rpm on an upshift, flare above 300 rpm), Ford's automatics feed the solenoid function codes and GM the clutch valve codes. It exists only on transmissions with at least six gears; MIL and trip count follow the manufacturer.

Likely causes

Fluid low or aged
Shift or clutch pressure valve for 5-6 sticking
Clutch or brake of 6th gear worn
Adaptives or software
Input or output speed sensor delivering wrong values

Symptoms

  • Harsh, delayed or missing 5-6 shift
  • Engine speed flares during the shift
  • Limp mode in a fixed gear, possibly MIL

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–3,500
Time1–10 h

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

Parts involved

transmission valve bodyshift solenoidtransmission clutchestransmission control module

Related codes

P0784P07DAP0780P0729P0735

References: law.cornell.edu, fordservicecontent.com.