Drivable short-term, but fix now to avoid damage.
This code means the measured gear ratio in third gear doesn't match the expected value, which typically points to slipping. Common causes include low or contaminated fluid, worn clutches or bands, or a faulty shift solenoid. Early diagnosis can sometimes limit the repair to fluid service or a solenoid rather than a full transmission overhaul.
$200 – $2500
Varies by vehicle and root cause.
You can manage short trips, but slipping in third gear builds heat and can worsen damage, so it's best to limit driving and get it inspected promptly.
Depending on the cause, a fluid service or solenoid fix may run $200 to $600, while internal repairs to clutches or bands can reach $1,500 to $2,500 or more.
It can be, since it indicates the transmission is slipping in third gear. Left unaddressed, it can lead to costly internal damage, so prompt diagnosis matters.
They're nearly identical issues but in different gears. P0734 flags an incorrect ratio in third gear, while P0733 flags it in second gear, both usually pointing to slipping.