P1733 — Transmission Slip Error

For Ford vehicles

third to fourth upshifting error

powertrain (engine/transmission)

Is it safe to drive?

Drive with caution Drive only if the transmission still shifts predictably, and avoid highway speeds. Driving with slipping or limp mode accelerates internal wear — every kilometre can add to the final repair bill.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm P1733 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the automatic transmission control for damage, corrosion, chafing or poor contact.
Subsystem check Check transmission fluid level and condition — dark, burnt fluid points to internal wear.
Subsystem check Read transmission-specific codes and live data (solenoid states, input/output speed) with a capable scanner.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P1733 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P1733 (parts and labor, USD, independent shop rates): Valve body repair or replacement: $700–$1,500; Transmission fluid service: $150–$350; Transmission rebuild or replacement: $2,500–$5,500; Replace a shift solenoid: $300–$800. Overall, fixing P1733 usually costs between $150 and $5,500. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

How much does it cost to fix P1733?

Valve body repair or replacement — $700–$1,500; Transmission fluid service — $150–$350; Transmission rebuild or replacement — $2,500–$5,500; Replace a shift solenoid — $300–$800. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

What are the symptoms of P1733?

Drivers most often notice: slipping between gears, Check Engine or transmission warning light on, no movement in severe cases, transmission stuck in one gear (limp mode).

How do I diagnose P1733 myself?

Start with a scan: confirm P1733, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the automatic transmission control, and verify the suspect component against live data before buying parts.

Will P1733 clear itself?

Sometimes P1733 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What does OBD2 code P1733 mean?

Transmission Slip Error (P1733): a powertrain (engine/transmission) fault affecting the automatic transmission control. Short, gentle driving to a shop is usually possible. Most often caused by faulty transmission speed sensor, valve body wear, low or degraded transmission fluid.

When your vehicle's computer stores code P1733, it's telling you that something inside the automatic transmission is slipping. The powertrain control module constantly watches how the transmission behaves, comparing actual gear engagement against what it expects. When that comparison shows a mismatch across multiple drive cycles, P1733 gets logged. This falls under the broader category of transmission control faults that OBD2 systems are designed to catch. The check engine light or transmission warning lamp will illuminate to alert you, and the module saves a snapshot of everything happening at that exact moment—engine speed, load, temperature, and vehicle speed—so you can replicate those conditions during diagnosis.

The automatic transmission relies on fluid pressure to engage gears and transfer power smoothly from the engine to the wheels. The control module commands shift solenoids and monitors speed sensors to confirm each shift happens correctly. When fluid condition deteriorates, sensors fail, or mechanical components wear, the transmission can slip—meaning the engine revs without corresponding acceleration or the car feels like it's hunting between gears. P1733 specifically flags that slip condition, though the root cause could be electrical, hydraulic, or mechanical.

Repair shops confirm P1733 by reading the stored freeze frame data first. That snapshot tells you whether the slip occurred at highway speed under light load or during a full-throttle upshift, which dramatically narrows your diagnostic focus. Always check for any accompanying transmission trouble codes before clearing anything—those secondary codes often point directly to the failing component rather than chasing the slip as a standalone problem.

Typical Symptoms

Noticeable gear slippage during acceleration or cruising
Illuminated Check Engine or transmission warning indicator
Transmission locked in a single gear (limp-home mode)
Harsh engagements or delayed shifts between gears
Shuddering or vibration at higher speeds
In severe cases, complete loss of forward or reverse movement

Common Causes

Insufficient or contaminated transmission fluid
Faulty input/output speed sensor
Damaged wiring or corroded connectors in the transmission harness
Worn internal components such as clutch plates or torque converter
Failed shift solenoid or pressure control solenoid
Valve body mechanical faults restricting hydraulic flow

Diagnostic Approach

Start by connecting a scan tool and recording all stored codes along with the freeze frame information associated with P1733. Replicate the recorded conditions—a specific speed, load, and temperature—during your road test to trigger the fault again if possible.

Next, research whether your vehicle has any technical service bulletins mentioning P1733. Manufacturers sometimes release software updates or known-fix campaigns that solve recurring transmission issues without physical repair. Search using your VIN on the manufacturer's website or through NHTSA.

Inspect the transmission wiring harness thoroughly. Look for frayed insulation, broken wires near connectors, and any signs of fluid intrusion at the connector seals. Poor electrical contact here can cause the control module to receive incorrect sensor data, triggering slip detection.

Drain and evaluate the transmission fluid. Burnt odor, dark discoloration, or metal particulate on the drain plug indicates internal wear. Even if the level appears adequate, degraded fluid cannot maintain the hydraulic pressure needed to prevent slip.

Use a diagnostic scanner capable of reading manufacturer-specific transmission data. Monitor solenoid operation, input and output shaft speeds, and line pressure readings while driving. A significant difference between engine rpm and output shaft rpm confirms slippage is occurring.

After addressing any obvious issues, clear P1733 and perform a complete drive cycle. The code should stay cleared if the underlying condition is resolved.

Repair Options and Costs

Transmission fluid service (drain, fill, and filter replacement): $150–$350. This is the first repair to attempt since low or dirty fluid causes most slip conditions.

Valve body repair or replacement: $700–$1,500. The valve body houses the passages and solenoids that direct fluid pressure. Repair involves cleaning and replacing worn components; full replacement covers all internal wear.

Shift solenoid replacement: $300–$800. Individual solenoids can fail electrically or become clogged with debris, preventing proper gear engagement.

Transmission rebuild or replacement: $2,500–$5,500. Internal mechanical failures involving clutches, bands, or the torque converter require this extensive repair.

Total Repair Cost

Most P1733 diagnoses end with a fluid service or solenoid replacement, keeping total costs near $150–$800. Full transmission teardown represents the upper end at $2,500–$5,500. Always pursue the cheapest probable cause first—transmission replacements are rarely necessary when fluid and electrical issues are addressed promptly.

Driving Safety Assessment

P1733 carries a caution severity rating. Limited local driving may be acceptable if the transmission still shifts and no harshness is present, but highway speeds should be avoided. Continued operation with active slip can rapidly destroy clutches and other internal parts, turning a $300 fix into a $4,000 transmission replacement. Have the vehicle inspected before any extended trip.