P0733 Code: Gear 3 Incorrect Ratio — Meaning & Fix

Sun West Transmissions — Glendale, AZ. Free estimates, honest diagnosis and a 3-year / 40,000-mile warranty on qualifying rebuilds and replacements.

What Does P0733 Mean?

P0733 is the OBD-II code for “Gear 3 Incorrect Ratio.” When your transmission computer commands third gear, it expects the input shaft and output shaft speeds to settle into a specific ratio. If the measured ratio is outside the allowed range for long enough, the computer stores P0733 and turns on the check engine light.

Third gear is the gear many vehicles use for city cruising between 30 and 45 mph, so this code often shows up on surface streets like 59th Avenue, 75th Avenue or Glendale Avenue, where you spend a lot of time in the middle gears.

Symptoms Drivers Notice

• RPM flare or slip on the 2-3 shift
• Third gear feels “soft” and the engine revs higher than normal at steady speed
• Delayed or missed 2-3 upshift, or the vehicle skips from second to fourth
• Harsh downshift into third when slowing
• Transmission locks into a fail-safe gear (limp mode)

What Causes P0733?

Worn Third-Gear Clutch Pack

Each transmission design applies a particular combination of clutches for third gear. On the GM 4L60E family, the 3-4 clutch pack is involved in both third and fourth, and it is a well-known weak spot. When it burns, drivers often see P0733 and P0734 together. We cover that failure in detail on our 4L60E 3-4 clutch failure page.

Hydraulic Pressure Loss

Worn sealing rings, cracked or hardened piston seals, a worn pump or a leaking accumulator can all reduce the pressure available to hold third gear. Many of these leaks grow worse as fluid temperature rises, which is common in Phoenix summers.

Shift Solenoid or Valve Body Faults

If the shift solenoid that controls the 2-3 shift sticks, or a valve in the valve body wears its bore, third gear may not apply fully. Electronic pressure control problems can also lower line pressure across all gears.

Low, Old or Contaminated Fluid

Low fluid causes aeration and pressure drops. Old fluid loses its friction modifiers. Fluid full of clutch debris can plug screens and passages.

Sensor Data Problems

A bad input or output speed sensor, or damaged wiring, can make the ratio look wrong even if the clutches are fine. A tech checks for related sensor codes and watches live data before blaming hard parts.

What You Can Check Before Coming In

• Fluid level and condition, if your vehicle has a dipstick (see how to check transmission fluid)
• Signs of leaks on the driveway or under the transmission pan
• Whether the slip happens only when hot, only on hills, or all the time
• Any other codes stored, which a parts store scan can show

Write down what you notice. Details such as “it slips going into third only after 20 minutes on the Loop 101” are very useful during diagnosis.

How Sun West Diagnoses P0733

We start by verifying the code and reviewing freeze-frame data, which shows speed, temperature and load at the moment the code set. Then we check fluid level and condition and road test with a scan tool, comparing commanded gear to actual input and output speeds. If the numbers point to a hydraulic leak, we may perform a line pressure test. A pan inspection tells us how much clutch material and metal is in the system.

From there, we explain the findings in plain language. Sometimes a solenoid, valve body or wiring repair is enough. If the clutch pack is burned, the fix is usually a transmission rebuild or replacement. See how we approach testing on our computer transmission diagnostics page.

Should You Keep Driving?

A transmission that is slipping in third is generating extra heat every time it shifts. Continued driving can turn a repair into a full rebuild by contaminating the fluid with friction material. Avoid towing or heavy loads, and stop driving if the vehicle will not move, slips heavily, overheats or smells burnt.

Cost to Fix P0733

There is no single price for P0733 because the cause decides the repair. For a GM 4L60E, our rebuild pricing starts from $2,795 with removal and installation included, and the heavy-duty 4L80E starts from $2,995. For any other unit, we give a free quote after diagnosis. Qualifying rebuilds and replacements carry our 3-year / 40,000-mile warranty with no deductible on covered repairs.

P0733 Code FAQ

Why do I have P0733 and P0734 at the same time?

On many transmissions, the same clutch pack or hydraulic circuit is used in both third and fourth gears, so one failure can set both codes.

Can additives fix a third gear slip?

Additives cannot replace worn friction material. At best they mask a symptom briefly, and they can complicate diagnosis.

Will clearing the code fix it?

No. The code will return when the computer sees the slip again, and clearing it erases helpful diagnostic data.