P0730 on Acura
Incorrect Gear Ratio
P0730 on Acura vehicles indicates incorrect gear ratio. Au7o has documented this code across 3 Acura models — most commonly on CL, TL, TLX. This code means the transmission computer detected that the actual gear ratio (calculated from input vs. output shaft speeds) does not match what it should be for the commanded gear. In other words, the transmission isn't delivering the correct gear, which often shows up as slipping, flaring RPM during shifts, or being stuck in the wrong gear. It can stem from internal mechanical wear, low or contaminated fluid, or faulty solenoids and sensors. The vehicle may shift harshly or enter limp mode. Typical repair costs on Acura range from $200 to $4,500, depending on the specific model and root cause.
Common Causes of P0730
- •Low or contaminated transmission fluid
- •Worn clutches or bands (internal slipping)
- •Faulty shift solenoids
- •Dirty or sticking valve body
- •Faulty input or output speed sensor
- •Internal hydraulic/line pressure problems
- •Torque converter problems
- •General high-mileage transmission wear
P0730 on Acura by Model
Acura CL(1 issue)
- 3.0CL automatic transmission slips and fails — flush is forbidden, filter is not serviceable1997-1999
The 1997-1999 3.0CL uses an automatic transmission specific to its V6 model family (the 2.2CL/2.3CL 4-cylinder variants do NOT share this transmission and are not affected). Owners and independent transmission shops widely report failures: slipping under load, not shifting out of 1st until warm, harsh shifts, and eventually total failure. Reports of repeat failures are common. NOTE: this transmission failure pattern is more severe and better documented on the 2nd-gen 3.2CL (2001-2003) than on the 1st-gen 3.0CL; the 1st-gen exhibits the same underlying weakness but at lower failure rates. A critical maintenance detail: this transmission has minimal internal filtration, and the filter is not serviceable without complete teardown. Owners who power-flush a slipping unit dislodge clutch debris and accelerate the failure rather than fix it.
Acura TL(2 issues)
- Automatic Transmission 3rd Gear Failure2004-2008
The third-generation TL automatic transmission is notorious for 3rd gear clutch pack failure, often between 80,000-120,000 miles. The 3rd gear clutch pack burns out due to insufficient fluid flow and a weak pressure regulator design, causing the transmission to slip, flare, or refuse to engage 3rd gear entirely.
- 1999 3.2TL 5-speed auto was the start of the famous Acura V6 transmission failures1999
1999 was the launch year of the 2nd-gen TL with the 3.2L J32A V6 and a new 5-speed automatic. This transmission family turned into one of the worst Acura defects of the early 2000s — torque converter failure, 3rd-gear clutch pack burn-up, blocked oil passages from debris, and complete failure became common. American Honda extended the transmission and torque converter warranties in 2003 (per TSB 02-027). The 1996-1998 TL uses the older 4-speed automatic which is generally reliable; the failure pattern is specifically the 5AT introduced for 1999. If you are car-shopping a 1999 TL, the model year alone does not tell you which transmission you have — the early-1999 carryover may have the older 4AT while the mid-year 2nd-gen launch got the 5AT. Check the build date and trans serial to know.
Acura TLX(1 issue)
- 9-Speed Automatic Transmission Shudder and Harsh Shifting2015-2020
The ZF 9HP 9-speed automatic transmission paired with the V6 in first-gen TLX models exhibits a pronounced shudder during low-speed acceleration and harsh shifts between 2nd and 3rd gear. The torque converter lockup strategy causes a noticeable vibration between 25-45 mph that worsens in warm weather.
Looking for P0730 on a different make?
View P0730 across all makes →Frequently Asked Questions
What does P0730 mean on Acura?▼
P0730 stands for "Incorrect Gear Ratio." This code means the transmission computer detected that the actual gear ratio (calculated from input vs. output shaft speeds) does not match what it should be for the commanded gear. In other words, the transmission isn't delivering the correct gear, which often shows up as slipping, flaring RPM during shifts, or being stuck in the wrong gear. It can stem from internal mechanical wear, low or contaminated fluid, or faulty solenoids and sensors. The vehicle may shift harshly or enter limp mode. On Acura specifically, this code is documented across 3 models.
What causes P0730 on Acura vehicles?▼
Common causes on Acura: Low or contaminated transmission fluid, Worn clutches or bands (internal slipping), Faulty shift solenoids, Dirty or sticking valve body, Faulty input or output speed sensor. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0730 on a Acura?▼
Repair costs on Acura range from $200 to $4,500, depending on the specific model and root cause.
Which Acura models have P0730 documented?▼
Au7o has documented P0730 on 3 Acura models: CL, TL, TLX.