Known Issues/P0734/Chrysler

P0734 on Chrysler

Gear 4 Incorrect Ratio

Critical1 Chrysler model affectedSystem: Transmission
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P0734 on Chrysler vehicles indicates gear 4 incorrect ratio. Au7o has documented this code across 1 Chrysler model — most commonly on Pacifica. This code means the Transmission/Powertrain Control Module detected an incorrect gear ratio in 4th gear. The module continuously compares input shaft speed to output shaft speed; if the ratio in 4th gear doesn't match the expected value, it sets P0734. This usually indicates the transmission is slipping or not fully engaging 4th gear due to a hydraulic, friction, or solenoid problem. Symptoms include slipping, flaring RPM, harsh or missed shifts, and possibly limp mode.

Common Causes of P0734

  • •Low or degraded/burnt transmission fluid
  • •Slipping clutch packs or worn friction elements in 4th gear
  • •Stuck or faulty shift solenoid
  • •Valve body / internal hydraulic leak or restriction
  • •Worn or failing torque converter
  • •Faulty input or output speed sensor
  • •Internal mechanical wear (bands, planetary gears)

P0734 on Chrysler by Model

Chrysler Pacifica(1 issue)

  • Transmission Harsh 3-4 Shift and Shudder (9-Speed)2017-2025

    The ZF 9HP 9-speed automatic transmission in the Pacifica exhibits harsh or jerky 3-4 shifts, shuddering during light throttle acceleration at 25-40 mph, and occasional hesitation when downshifting. The 9-speed has had multiple software calibration updates since launch, and the adaptive learning can become confused by varied driving patterns. Cold weather worsens the harsh shifting. The issue persists across multiple model years despite ongoing TSBs.

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Frequently Asked Questions

What does P0734 mean on Chrysler?▼

P0734 stands for "Gear 4 Incorrect Ratio." This code means the Transmission/Powertrain Control Module detected an incorrect gear ratio in 4th gear. The module continuously compares input shaft speed to output shaft speed; if the ratio in 4th gear doesn't match the expected value, it sets P0734. This usually indicates the transmission is slipping or not fully engaging 4th gear due to a hydraulic, friction, or solenoid problem. Symptoms include slipping, flaring RPM, harsh or missed shifts, and possibly limp mode. On Chrysler specifically, this code is documented across 1 model.

What causes P0734 on Chrysler vehicles?▼

Common causes on Chrysler: Low or degraded/burnt transmission fluid, Slipping clutch packs or worn friction elements in 4th gear, Stuck or faulty shift solenoid, Valve body / internal hydraulic leak or restriction, Worn or failing torque converter. Specific causes vary by model and year — see the per-model sections below.

How much does it cost to fix P0734 on a Chrysler?▼

Repair costs vary widely depending on the root cause and specific Chrysler model.

Which Chrysler models have P0734 documented?▼

Au7o has documented P0734 on 1 Chrysler model: Pacifica.

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