P0733 on 2006-2013 Chevrolet Silverado 1500: Gear 3 Ratio Error Causes and Fixes

What's Unique About the 2006-2013 Chevrolet SILVERADO 1500

This year range covers two distinct Silverado generations and their primary transmissions: the GMT800 (2006-2007 Classic) with the 4L60-E 4-speed, and the GMT900 (2007-2013) which used the 4L60-E initially but primarily featured the 6L80 6-speed. While P0733 can occur on both, the 4L60-E is well-known for issues with the 3-4 clutch pack, a common cause for this code that often results in a complete loss of 3rd and 4th gear. On the 6L80, the issue is more frequently linked to failures within the Transmission Electro-Hydraulic Control Module (TEHCM), which houses the solenoids, or a broken 3-5-R wave plate, a known weak point in this transmission.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Generation note: The 2006-2013 range includes the end of the GMT800 generation (often called 'Classic' in 2007) and the GMT900 generation (2007-2013). The GMT800s almost exclusively used the 4-speed 4L60-E. The GMT900s used the 4L60-E in early V6 and some V8 models, but most have the 6-speed 6L80. Knowing your specific transmission (check the RPO code sticker in the glovebox for 'M30' for 4L60-E or 'MYC' for 6L80) is critical for diagnosis.

Symptoms You May Notice

• Check Engine Light is on, often accompanied by P0700 (General Transmission Fault).
• Transmission slipping, where engine RPMs increase but vehicle speed does not, especially when shifting to or driving in 3rd gear.
• Harsh, delayed, or failed shifts into 3rd gear.
• Vehicle enters "limp mode," often getting stuck in a single gear to prevent further damage.
• Reduced fuel efficiency due to improper gear engagement.
• Vehicle may feel like it has a lack of power or struggles to accelerate, particularly in the 25-45 mph range.

Most Likely Causes

1. Low or Dirty Transmission Fluid 🔴 High Probability → Shop Transmission Assembly Many owners neglect transmission fluid service intervals. Low fluid prevents proper hydraulic pressure for clutch engagement, and dirty/burnt fluid can clog passages and cause solenoids to stick.
   How to confirm: Check the transmission fluid dipstick (if equipped on 4L60-E) for level and condition. Fluid should be bright red and not smell burnt. For sealed transmissions (like many 6L80s), this must be checked via a fill plug at a specific temperature. Dark, gritty fluid suggests clutch material is present.
   Typical fix: Perform a fluid and filter change with the correct fluid (Dexron VI). If fluid is very low, the source of the leak must be found and repaired.
   Est. part cost: $50-$150
2. Faulty Shift Solenoid / TEHCM 🟡 Medium Probability → Shop Transmission Valve Body On the 4L60-E, the 'B' (2-3) shift solenoid can fail. On the 6L80, the entire solenoid block is integrated into the TEHCM, which is a very common failure point, causing various shift codes including P0733.
   How to confirm: A professional scanner can command the solenoid to check its operation. On a 4L60-E, the solenoid can be tested with a multimeter for resistance (typically 20-30 ohms) after removing the pan. For a 6L80, TEHCM failure is often diagnosed by elimination after fluid/filter service doesn't resolve the issue.
   Typical fix: For 4L60-E, drop the pan and replace the 'B' shift solenoid (ACDelco #24230298). For 6L80, replace the entire TEHCM assembly (e.g., ACDelco #24256861 for 2010-13), which requires programming to the vehicle's VIN.
   Est. part cost: $40-$100 for a 4L60-E solenoid; $400-$800 for a 6L80 TEHCM.
3. Worn 3-4 Clutch Pack (4L60-E Internal Damage) 🟡 Medium Probability The 3-4 clutch pack is the most widely documented weak point in the 4L60-E transmission. The clutches wear out, especially after 100k miles, and can no longer hold hydraulic pressure, causing a slip specifically when 3rd and 4th gear are commanded.
   How to confirm: After ruling out fluid and solenoids, finding significant clutch material (fine black grit) in the transmission pan is a strong indicator. The ultimate confirmation is a transmission teardown. A common symptom is having 1st and 2nd gear, but the engine revs freely (flares) when it attempts to shift into 3rd. 🎬 See why a 3-4 shift flare might be failed seals.
   Typical fix: Requires a complete transmission rebuild or replacement. During a rebuild, upgraded clutch packs are often installed.
   Est. part cost: $1500-$4000+
4. Valve Body Issues ⚪ Low Probability → Shop Transmission Valve Body Debris from dirty fluid or normal wear can cause check balls to stick or wear bores in the valve body, leading to pressure loss that affects clutch engagement. This can happen on both the 4L60-E and 6L80.
   How to confirm: Requires removal and inspection of the valve body. This is often done at the same time as a solenoid replacement. A pressure test can also point to internal hydraulic leaks.
   Typical fix: Cleaning the valve body, replacing worn components with a kit (e.g., Sonnax), or replacing the entire valve body assembly.
   Est. part cost: $200-$700

Rare But Worth Checking

• Faulty Transmission Control Module (TCM): → Shop Transmission Assembly While rare, a faulty TCM can misinterpret sensor data or fail to command shifts correctly. On 6L80 models, this is a much more common issue as the TCM is integrated with the solenoids in the TEHCM. This should only be considered after all mechanical and hydraulic possibilities are exhausted on 4L60-E models.
• Damaged Wiring: Wiring to the transmission can be damaged by heat, debris, or corrosion, leading to intermittent signals. TSB 22-NA-187 points to potential water intrusion and corrosion at the transfer case actuator connector, which can cause various electrical issues.
• Broken 3-5-R Wave Plate (6L80): A known failure point in early 6L80 transmissions. When this wave plate breaks, pieces can travel through the transmission, damaging other components and causing shifting problems, though it often presents with other codes or a loss of Reverse gear first.

Diagnosis Steps

1. Check the transmission fluid level and condition. If it's low, top it off and check for leaks. If it's dark, burnt, or contains metallic particles, suspect internal damage.
2. Scan the TCM for all stored trouble codes. Note any other codes besides P0733, especially P0700 or other gear ratio codes.
3. Perform a test drive to confirm the symptoms. Note if the slip happens during the 2-3 shift or while holding 3rd gear.
4. If fluid is okay, the next step is to drop the transmission pan. Inspect the fluid in the pan for clutch material (black sludge) or metal shavings.
5. With the pan off, inspect the wiring to the solenoids. For a 4L60-E, test the resistance of the 'B' (2-3) shift solenoid with a multimeter (should be 20-40 ohms).
6. If solenoids and wiring test good on a 4L60-E, the problem is almost certainly internal (worn 3-4 clutches).
7. For a 6L80, if the fluid and filter change does not resolve the issue, the next logical step is often the replacement of the TEHCM/solenoid pack 🎬 Watch this essential guide before removing your 6L80 TCM., as they are the most common failure point.
8. If all else fails, professional diagnosis involving hydraulic pressure testing is required to confirm an internal mechanical failure before recommending a rebuild.

Parts You'll Likely Need

• Transmission Filter and Gasket Kit (OEM #24236933 (4L60-E Deep Pan), 24236934 (6L80)) — Required for any job that involves dropping the transmission pan, such as a fluid change or solenoid replacement.
  Trusted brands: ACDelco, ATP
  OEM price range: $40-$70
  Aftermarket price range: $20-$40
• Shift Solenoid (4L60-E) / TEHCM (6L80) (OEM #24230298 (4L60-E 'A'/'B' Solenoid), 24256861 (6L80 TEHCM, 2010-13)) — The 2-3 shift solenoid ('B') is a common electrical failure on the 4L60-E. On the 6L80, the entire TEHCM assembly is the most frequent point of failure for electronic and hydraulic shifting faults.
  Trusted brands: ACDelco, Bosch
  OEM price range: $60-$120 (4L60-E Solenoid), $500-$800 (6L80 TEHCM)
  Aftermarket price range: $40-$80 (4L60-E Solenoid), $400-$700 (6L80 TEHCM)

Related Codes That Often Appear With This One

• P0700 — This is a general transmission fault code. It means the TCM has stored a specific code (like P0733) and has requested the main engine computer (PCM) to turn on the Check Engine Light.
• P0731, P0732, P0734 — These codes indicate incorrect gear ratios for 1st, 2nd, and 4th gear, respectively. Seeing them alongside P0733 points to a widespread internal transmission problem, not just an isolated 3rd gear issue. The provided TSB #PIP4379M lists these codes together as a known issue.
• P0894 — This code means 'Transmission Component Slipping'. It is a more general slip code that frequently appears with specific gear ratio codes like P0733, confirming the TCM is detecting slip.

Technical Service Bulletins (TSBs) & Recalls

• Bulletin #PIP4379M: Addresses multiple transmission diagnostic trouble codes including P0733, related to delayed engagement or slipping.
• Bulletin #22-NA-187: Addresses potential water intrusion and corrosion at the transfer case actuator harness connector, which can cause various electrical faults.

Platform-Specific Known Issues

• TSB PIP4379M - General Diagnostic Guidance: Technical Service Bulletin PIP4379M was issued for a variety of transmission codes, including P0733. It addresses conditions like delayed engagement or slipping but does not provide a specific repair. Instead, it directs technicians to follow standard diagnostic procedures, essentially acknowledging a known pattern of internal transmission faults without offering a shortcut to the fix.
• 4L60-E 3-4 Clutch Pack Failure: A well-documented issue where the transmission loses 3rd and 4th gears. A user on LS1Tech.com described rebuilding their 4L60-E from a 2004 Silverado after finding the '3-4 clutch pack was completely burned out' and the fluid was 'thick black burnt'. This is a classic failure scenario for P0733 on this transmission.
• 6L80 TEHCM / Valve Body Failure: → Shop Transmission Valve Body On 6L80-equipped trucks, P0733 is more often an electronic or hydraulic control issue. A YouTuber, 'life with Derrick', documented solving his 6L80 issues on an '07 Yukon Denali by replacing the entire valve body and TEHCM assembly after getting rebuild quotes of over $4000. He noted symptoms of harsh engagement from a stop and loud solenoid noises, which were resolved with the new part.

Mechanic-Grade Diagnostic Values

• 4L60-E Shift Solenoid (1-2 or 2-3) Resistance — expected: 20-40 Ohms (20-25 Ohms is a stronger indicator of a good solenoid).. Failure: A reading outside this range (open or shorted) indicates a failed solenoid.
• 4L60-E EPC (Pressure Control) Solenoid Resistance — expected: 3.5-8.0 Ohms at 68°F.. Failure: Resistance outside the specified range.
• 4L60-E Line Pressure at Idle (in Drive) — expected: 55-65 psi for a stock unit.. Failure: Significantly lower pressure indicates a weak pump, internal leak, or clogged filter.
• 6L80 Shift Solenoid (On/Off Type) Resistance — expected: 20-40 Ohms.. Failure: A reading outside this range indicates a failed solenoid within the TEHCM.
• 6L80 Pressure Control Solenoid (PWM Type) Resistance — expected: 3-8 Ohms.. Failure: A reading outside this range points to a fault in the TEHCM.

Scan Tool Commands That Help

• Tech2 / GDS2: Solenoid Activation / Bidirectional Control — After checking fluid, use this to command individual shift solenoids on and off. A lack of an audible 'click' from the transmission pan suggests a dead solenoid or wiring issue.
• GDS2 or equivalent: Automated Solenoid Cleaning Process (6L80) — For 6L80 transmissions with solenoid performance codes, this function cycles all solenoids to flush out potential debris as a first step before considering TEHCM replacement.
• GM SPS2 / Techline Connect: Fast Learn / Reset Adapts — This is a mandatory step after installing and programming a new 6L80 TEHCM. It allows the module to quickly learn clutch volumes and ensure proper shift quality.

Wiring & Ground Locations

• Transmission Main Connector (4L60-E) — On the passenger side of the transmission case, it is a round 20-pin connector.. This is the primary connection point for testing solenoid resistance from outside the transmission, allowing a technician to diagnose electrical faults without dropping the pan.
• TEHCM Main Connector (6L80) — The 16-pin connector passes through the transmission case to connect the vehicle harness to the internal TEHCM.. Damage or corrosion at this connector can interrupt communication between the vehicle and the TEHCM, causing various codes including P0733.

Real Owner Repair Stories

• YouTube Commenter (Not specified, but applicable to computer-controlled transmissions.) — Transmission shifting problems.
  ❌ Tried (didn't work) Replacing the shift solenoids, which only fixed the issue for a few months.
  ✅ What actually fixed it The root cause was a faulty engine coolant temperature sensor. The bad sensor data was affecting the transmission's shift logic. Replacing the temperature sensor and IAC valve resolved the transmission issues permanently.
• Transmission Repair Shop Video (GM vehicle with 4L60-E, common on Silverado.) — Slipping in 3rd gear, burnt 3-4 clutches.
  ❌ Tried (didn't work) A standard rebuild focusing only on clutches and seals would have failed again quickly.
  ✅ What actually fixed it The technician performed a bench air test on the input drum and discovered a large crack where the input shaft is pressed in. This crack prevented the 3-4 clutch pack from holding hydraulic pressure. The final fix was replacing the entire input drum assembly.

When the Usual Fixes Don't Work

• While P0733 points directly at the transmission, external inputs can be the root cause. In one documented case, a technician replaced shift solenoids, which only provided a temporary fix. The ultimate cause was a faulty engine coolant temperature sensor sending incorrect data to the computer, which in turn commanded incorrect shift pressures and timing. This highlights the importance of checking for other non-transmission DTCs and evaluating engine sensor data, as the TCM's behavior is dependent on inputs from the ECM.

OEM Part Supersession History

• e.g., 24241350, 24252114 → e.g., 24256861, 24256863 — The 6L80 TEHCM was updated around 2010 to include improved solenoids and a better pressure manifold gasket to address common failure points in earlier models.
  Heads up: TEHCMs are not cross-compatible between year ranges (e.g., a 2011 TEHCM will not work in a 2008 truck). Using the wrong part number will result in a no-start condition or immediate limp mode. The correct TEHCM must be installed and then programmed to the vehicle's VIN.

Model Year Variations Within This Range

• 2007-2009: Early GMT900 trucks with the 6L80 used a first-generation TEHCM (e.g., part #24252114) that was more prone to internal pressure switch failures.
• 2010-2013: Later models in this range used an updated TEHCM (e.g., part #24256861) with more robust solenoids and improved internal components, making them more reliable than the earlier design.