P0773 on 2011-2015 Kia Forte: Shift Solenoid 'E' Causes and Fixes

What's Unique About the 2011-2015 Kia FORTE

The 2011-2015 Kia Forte uses a 6-speed automatic transmission (model A6GF1) that is known to have issues with its shift solenoids. Kia acknowledged this by issuing a Technical Service Bulletin (TSB #TSBTRA051R1) that specifically lists P0773 and advises technicians to replace the solenoids rather than the entire transmission. This indicates a higher-than-average failure rate for this specific component on this platform and its platform mates like the Hyundai Elantra and Kia Soul.

Diagnostic Flowchart

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

Generation note: This range covers the end of the first generation Forte (TD, 2011-2013) and the start of the second generation (YD, 2014-2015). Both generations used the A6GF1 6-speed automatic transmission for the 1.6L engine (and the similar A6MF1 for 1.8L/2.0L engines), so this issue and its fixes apply to the entire 2011-2015 year range.

Symptoms You May Notice

• Harsh, jerky, or delayed shifts.
• Transmission getting stuck in one gear (limp mode).
• Illuminated Check Engine Light.
• Transmission slipping (engine RPMs rise without an increase in speed).
• Decreased fuel economy.
• Transmission overheating.
• Inability to shift into certain gears, or shift at all.
• Engine has misfire-like symptoms or feels like it's hesitating.

Most Likely Causes

1. Failed Shift Solenoid 'E' 🔴 High Probability → Shop Transmission Valve Body As documented in Kia TSB #TSBTRA051R1, the shift solenoids in the 6-speed automatic transmission are a known failure point. The internal coil of the solenoid can fail, creating an open or short circuit. This is the most common cause for P0773.
   How to confirm: A mechanic can test the solenoid's resistance with a multimeter. For the A6GF1/A6MF1, the on/off shift solenoids (like 'E', also known as SS-A) should have a resistance of 10-11 Ohms. 🎬 Watch: How to test and clean your transmission solenoids. A reading outside this range indicates a failed solenoid. This requires accessing the solenoid inside the transmission.
   Typical fix: Replace the faulty shift solenoid. Often, solenoids are replaced as a complete pack or block. The TSB explicitly states to replace the solenoids, not the transaxle.
   Est. part cost: $60-$150
2. Low or Dirty Transmission Fluid 🟡 Medium Probability → Shop Transmission Assembly While not unique to this car, the A6GF1 transmission is sensitive to fluid condition. Burnt or contaminated fluid can cause solenoid valves to stick or malfunction.
   How to confirm: Check the transmission fluid level and condition. The fluid should be at the correct level, red in color, and not smell burnt. The correct fluid for this transmission is Kia/Hyundai SP-IV ATF.
   Typical fix: Perform a transmission fluid drain and fill, or a complete fluid flush if the fluid is very contaminated. Replace the transmission filter at the same time.
   Est. part cost: $70-$140 for SP-IV fluid and filter
3. Damaged Wiring or Connectors ⚪ Low Probability
   How to confirm: Visually inspect the wiring harness leading to the transmission for any signs of damage, corrosion, or loose connections at the main transaxle connector. A mechanic can perform a continuity test on the solenoid circuit from the TCM connector to the transmission connector.
   Typical fix: Repair or replace the damaged section of the wiring harness or the connector. In some cases, the internal transmission wire harness that connects to the solenoids may fail.
   Est. part cost: $20-$100 for external repairs, $100-$200 for internal harness

Rare But Worth Checking

• Faulty Transmission Control Module (TCM): → Shop Transmission Assembly This is rare. A faulty TCM will usually trigger other codes in addition to P0773. It should only be considered after all other possibilities, especially the solenoid and wiring, have been ruled out.
• Faulty Brake Light Switch: While it won't typically cause P0773 directly, a faulty brake light switch is a very common failure on these vehicles and can cause related issues like being unable to shift out of Park. Since it's an inexpensive and easy part to check, it's worth confirming your brake lights work correctly when diagnosing any transmission shifting problem.

Diagnosis Steps

1. Scan the vehicle's computer for P0773 and any other related trouble codes.
2. Check the level and condition of the automatic transmission fluid (ATF). Ensure it is the correct type (SP-IV). Top off or replace if necessary.
3. Inspect the external transmission wiring harness and connectors for any visible damage, corrosion, or loose connections.
4. If fluid and wiring are okay, the next step is to gain access to the solenoids by draining the fluid and removing the transmission oil pan.
🎬 See this walkthrough on removing the valve body and solenoids.
5. Identify Shift Solenoid 'E' (also called SS-A). It is one of the two black, on/off type solenoids.
6. Test the resistance of Shift Solenoid 'E' using a multimeter. The specification is 10-11 Ohms. If the reading is open (infinite resistance) or shorted (zero resistance), the solenoid is bad.
7. If the solenoid fails the resistance test, it must be replaced. It is highly recommended to replace the entire set of 8 solenoids as a preventative measure.
8. If the solenoid tests good, a more in-depth diagnosis of the internal transmission harness, the main connector, or the Transmission Control Module (TCM) is required.

Parts You'll Likely Need

• Automatic Transmission Control Solenoid (OEM #46313-3B030 (This is the common part number for the on/off shift solenoids A/B in the A6GF1/A6MF1 family). A full kit is often sold.) — This is the most common cause of code P0773 on this vehicle, as confirmed by a manufacturer TSB. The solenoid itself fails electrically.
  Trusted brands: Standard Motor Products, WVE, Genuine Hyundai/Kia
  OEM price range: $80-$150 (for one), $250-$400 (for a full kit)
  Aftermarket price range: $40-$90 (for one), $130-$250 (for a full kit)
• Automatic Transmission Fluid and Filter Kit (OEM #Fluid: Kia/Hyundai SP-IV ATF) — Fresh fluid and a new filter are required when replacing the solenoid and can sometimes resolve the issue if it was caused by contamination.
  Trusted brands: Genuine Kia/Hyundai, Idemitsu, Valvoline MaxLife (check for SP-IV compatibility)
  OEM price range: $80-$150
  Aftermarket price range: $50-$100

Related Codes That Often Appear With This One

• P0741, P0743, P0748, P0753, P0758, P0763, P0768, P1778, P2709 — These are all codes related to other solenoids in the same 6-speed automatic transmission. Kia groups them together in TSB #TSBTRA051R1, indicating a common failure pattern for the solenoid assembly. A failure of one solenoid often suggests others may be weak or failing.

Technical Service Bulletins (TSBs) & Recalls

• TSBTRA051R1: Addresses multiple solenoid-related DTCs (P0741, P0743, P0748, P0753, P0758, P0763, P0768, P0773, P1778, P2709) on 6-speed automatic transaxles. It advises replacing the specific solenoids if codes are present and explicitly states 'Do not replace the transaxle'.

Platform-Specific Known Issues

• Kia issued Technical Service Bulletin #TSBTRA051R1 for multiple vehicles with the 6-speed automatic transmission, including the Forte. It notes that DTCs like P0773 are likely caused by a faulty solenoid and that the solenoid should be replaced, not the entire transaxle.
• Owners on forums report that this failure is common and often presents as the car getting stuck in 3rd gear (limp mode) with the check engine light on. The typical successful repair is replacing the entire solenoid block while the valve body is removed.

Mechanic-Grade Diagnostic Values

• Resistance of On/Off Shift Solenoids (SS-A / SS-B) — expected: 10 - 11 Ohms. Failure: A reading of infinite resistance (open) or near-zero resistance (short).
• Resistance of Variable Force Solenoids (VFS) — expected: 5.3 Ohms (approx.). Failure: A reading significantly different from 5.3 Ohms.
• Solenoid Circuit Voltage (commanded on) — expected: 9 - 12 V. Failure: Voltage outside this range suggests a problem with the wiring or the TCM.

Scan Tool Commands That Help

• Kia GDS (Global Diagnostic System): Actuation Test — The GDS, which is the OEM scan tool for Kia up to 2018, can be used to command individual solenoids on and off. This allows a technician to verify if the TCM is sending the command and if the solenoid clicks in response, helping to isolate the fault between the TCM, wiring, and the solenoid itself without having to immediately open the transmission pan.

Wiring & Ground Locations

• Transmission Ground Wiring Assembly — There is a specific ground wire that connects from the transmission bellhousing area to the chassis. The OEM part number for this ground on the 2.0L Forte is 91860-1M120 or 91860-1M140 depending on the specific model year and transmission type.. A poor ground connection for the transmission can cause a variety of electrical faults and erratic behavior in electronically controlled components like shift solenoids. Verifying this ground is clean and tight is a crucial step in diagnosing any electrical transmission code.
• Main Transmission Connector — The main electrical connector for the transmission is located on the top of the transmission case, accessible from under the hood after removing the battery and battery tray.. This is the primary connection point for all solenoid circuits. It's a critical place to check for corrosion, bent pins, or damage before proceeding to internal transmission diagnosis.

OEM Part Supersession History

• 46313-3B020 → 46313-3B030 — Standard part revision and improvement by the manufacturer.
  Heads up: The parts are interchangeable, with 46313-3B030 being the current replacement for the older number.

Model Year Variations Within This Range

• 2011-2015: The 1.6L engine typically used the A6GF1 transmission, while the 1.8L and 2.0L engines used the similar but slightly larger A6MF1/2. While they are in the same family and share the same TSB and common solenoid failures, it's important to verify the exact transmission model when ordering parts as some internal components may differ.
• 2014-2015: The second generation (YD) Forte was introduced in 2014 with new 1.8L and 2.0L engines, but they continued to use the 6-speed automatic transmission family (A6MF1) that is prone to this issue. The diagnostic and repair process remains consistent with the earlier 2011-2013 models covered by the TSB.