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Service bulletins for the 2014 Kia Optima

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

353 on file from NHTSA, as of 2026-10-19.

About P1326 on the 2014 Kia Optima: what the code means, and the bulletins and recalls about the same components.

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Only bulletins with trouble code: P1326 are shown. Show all

Bulletins, newest first
PI2104YZ_TSB_R12024-11-13. Service bulletin. ENGINE. TECHNICAL SERVICE BULLETIN: PRODUCT IMPROVEMENT CAMPAIGN: SUBSEQUENT REPAIR ACTION: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI2104Y/Z) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information related to the Technical Service Bulletin previously published in (PI2104) titled “Knock Sensor Detection System - ECU Logic Improvement” for 2014-2016MY Optima (TF HEV) vehicles equipped with Theta 2.4L MPI engine, produced from December 11, 2013 through July 22, 2015. Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below return to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1803YZ_TSB_R72024-04-03. Service bulletin. ENGINE AND ENGINE COOLING. TECHNICAL SERVICE BULLETIN: PRODUCT IMPROVEMENT CAMPAIGN: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1803Y/Z) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information related to the Technical Service Bulletin previously published PI1803 titled "Knock Sensor Detection System - ECU Logic Improvement" equipped w/THETA II engine. Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below returns to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1802YZ_TSB_R72024-04-03. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. TECHNICAL SERVICE BULLETIN: PRODUCT IMPROVEMENT CAMPAIGN: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1802Y/Z) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information related to the Technical Service Bulletin previously published PI1802 titled "Knock Sensor Detection System - ECU Logic Improvement"; equipped w/THETA II engine. Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below returns to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI2104YZ_TSB2023-08-02. Service bulletin. ENGINE AND ENGINE COOLING. SUBSEQUENT REPAIR ACTION: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI2104Y/Z) - This bulletin provides information related to the Technical Service Bulletin previously published in (PI2104) titled "Knock Sensor Detection System - ECU Logic Improvement" for 2014-2016MY Optima (TF HEV) vehicles equipped with Theta 2.4L MPI engine, produced from December 11, 2013 through July 22, 2015. Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below return to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1803YZ_TSB_R62022-01-04. Service bulletin. ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1803Y/Z) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information related to the Technical Service Bulletin previously published PI1803 titled "Knock Sensor Detection System - ECU Logic Improvement" equipped w/THETA II engine. Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below returns to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1802YZ_TSB_R62022-01-04. Service bulletin. ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1802Y/Z) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information related to the Technical Service Bulletin previously published PI1802 titled "Knock Sensor Detection System - ECU Logic Improvement" equipped w/THETA II engine. Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below returns to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1803YZ_TSB_R52021-12-01. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1803Y/Z) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information related to the Technical Service Bulletin previously published PI1803 titled "Knock Sensor Detection System - ECU Logic Improvement" equipped w/THETA II engine. Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below returns to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1802YZ_TSB_R52021-12-01. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1802Y/Z) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information related to the Technical Service Bulletin previously published PI1802 titled "Knock Sensor Detection System - ECU Logic Improvement" equipped w/THETA II engine. Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below returns to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1803YZ_TSB_R42020-12-01. Service bulletin. ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1803Y/Z) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information related to the Technical Service Bulletin previously published in July 2018 (PI1803, Rev 10, 03/16/2020) titled "Knock Sensor Detection System - ECU Logic Improvement" equipped w/THETA II engine. Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below returns to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1802YZ_TSB_R42020-12-01. Service bulletin. ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1802Y/Z) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information related to the Technical Service Bulletin previously published in July 2018 (PI1802 Rev 10, 03/16/2020) titled “Knock Sensor Detection System - ECU Logic Improvement” equipped w/THETA II engine. Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below returns to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1803YZ_TSB_R32020-08-03. Service bulletin. ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN - ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1803Y/Z_Rev3) - This bulletin has been revised to include additional information. This bulletin provides information related to the Technical Service Bulletin previously published in July 2018 (PI1803, Rev 10, 03/16/2020) titled "Knock Sensor Detection System - ECU Logic Improvement".
PI1802YZ_TSB_R32020-08-03. Service bulletin. ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN - ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1802Y/Z_Rev3) - This bulletin has been revised to include additional information. - This bulletin provides information related to the Technical Service Bulletin previously published in July 2018 (PI1802 Rev 10, 03/16/2020) titled "Knock Sensor Detection System - ECU Logic Improvement".
PI1802YZ_TSB_R22020-08-03. Service bulletin. ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN - ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1802Y/Z_Rev2) - This bulletin has been revised to include additional information. This bulletin provides information related to the Technical Service Bulletin previously published in July 2018 (PI1802 Rev 10, 03/16/2020) titled "Knock Sensor Detection System - ECU Logic Improvement".
PI1803YZ_TSB_R22020-07-06. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. TSB: PRODUCT IMPROVEMENT CAMPAIGN: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1803Y/Z) - This bulletin has been revised to include additional information. This bulletin provides information related to the Technical Service Bulletin previously published in July 2018 (PI1803, Rev 10, 03/16/2020) titled "Knock Sensor Detection System - ECU Logic Improvement". Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below return to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1803YZ_TSB_R12020-05-05. Service bulletin. ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN: TSB - ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1803Y/Z) - This bulletin has been revised to include additional information.This bulletin provides information related to the Technical Service Bulletin previously published in July 2018 (PI1803, Rev 10, 03/16/2020) titled "Knock Sensor Detection System - ECU Logic Improvement". Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below return to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1803WX_TSB_R5C2020-05-05. Service bulletin. ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN: TSB - ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1803W/X) - CLOSED - This bulletin has been superseded by PI1803Y/Z.
PI1802YZ_TSB_R12020-05-05. Service bulletin. ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1802Y/Z) - This bulletin has been revised to include additional information. This bulletin provides information related to the Technical Service Bulletin previously published in July 2018 (PI1802 Rev 10, 03/16/2020) titled "Knock Sensor Detection System - ECU Logic Improvement". Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below return to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1802WX_TSB_R7C2020-05-05. Service bulletin. ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN: TSB_R7 - ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1802W/X) - CLOSED - SUPERSEDED BY PI1802Y/Z.
PI1803Y/Z_TSB2020-04-07. Service bulletin. ENGINE AND ENGINE COOLING. PRODUCT IMPROVEMENT CAMPAIGN: TSB - ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1803Y/Z) - This bulletin has been revised to include additional information. This bulletin provides information related to the Technical Service Bulletin previously published in July 2018 (PI1803, Rev 10, 03/16/2020) titled "Knock Sensor Detection System - ECU Logic Improvement". Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below return to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1802YZ_TSB2020-04-07. Service bulletin. ENGINE AND ENGINE COOLING:COOLING SYSTEM. PRODUCT IMPROVEMENT CAMPAIGN: TSB - ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1802Y/Z) - This bulletin has been revised to include additional information. This bulletin provides information related to the Technical Service Bulletin previously published in July 2018 (PI1802 Rev 10, 03/16/2020) titled Knock Sensor Detection System - ECU Logic Improvement. Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below return to the dealer with Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance).
PI1802WX_TSB_R72020-02-03. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; ELECTRICAL SYSTEM:WIRING. PRODUCT IMPROVEMENT CAMPAIGN: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1802W/X) - This bulletin has been revised to include additional information.This bulletin provides information related to the Technical Service Bulletin previously published in July 2018 (PI1802, Rev 6, 01/31/2019) titled "Knock Sensor Detection System - ECU Logic Improvement". Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below returns to the dealer with Diagnostic Trouble Code (DTC), P1326.
PI1803WX_TSB_R52019-12-09. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; ENGINE AND ENGINE COOLING. TSB: PRODUCT IMPROVEMENT CAMPAIGN PI1803W/X_R5: ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326 (PI1803W/X) - This bulletin has been revised to include additional information. This bulletin provides information related to the Technical Service Bulletin previously published in November 2018 (PI1803, Rev 1, 01/02/2018) titled "Knock Sensor Detection System - ECU Logic Improvement". Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below returns to the dealer with Diagnostic Trouble Code ("DTC"), P1326.
PI1802WX_TSB_R62019-12-09. Service bulletin. ENGINE AND ENGINE COOLING. TECHNICAL SERVICE BULLETIN PI1802W/X (Rev 6) - PRODUCT IMPROVEMENT CAMPAIGN - ENGINE REPLACEMENT INSTRUCTIONS - This bulletin has been revised to include additional information. This bulletin provides information related to the Technical Service Bulletin previously published in July 2018 (PI1802, Rev 6, 01/31/2019) titled '"Knock Sensor Detection System - ECU Logic Improvement". Specifically, this bulletin provides instructions on which procedures to follow if, after installation of the KSDS, any one of the subject vehicles below returns to the dealer with Diagnostic Trouble Code ("DTC"), P1326.
PI1802_TSB_R72019-10-03. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM. PRODUCT IMPROVEMENT CAMPAIGN - KNOCK SENSOR DETECTION SYSTEM - ECU LOGIC IMPROVEMENT (PI1802) - This bulletin provides information related to a software update to the Engine Control Unit (ECU) to install the Knock Sensor Detection System (KSDS) in order to protect the engine from excessive connecting rod bearing damage. The KSDS detects vibrations indicating the onset of excessive connecting rod bearing wear. It is designed to alert the driver at an early stage of bearing wear before the occurrence of severe engine damage, including engine failure. If vibrations caused by bearing wear start to occur, the Malfunction Indicator Lamp (MIL) will blink continuously, and the vehicle will be placed in Limp Home Mode. This will reduce further damage to the engine and ensure that the vehicle occupants are not exposed to the risk of a more severe engine failure. At that time, Diagnostic Trouble Code (“DTC”) P1326, specific to the KSDS, will be recorded in the ECU. The vehicle can continue to be operated for a limited time in Limp Home Mode, but it will accelerate slowly and have a reduced maximum speed. Also, engine RPMs will be limited to approximately 1800-2000 RPM.
TSBENG205_R12019-04-30. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM. TSB: SERVICE ACTION: WIRING SIGNAL INTERFERENCE CHECK & ENGINE NOISE INSPECTION (SA379) - This bulletin provides information related to an expanded diagnostic test that is now required on a number of vehicles previously diagnosed with Diagnostic Trouble Code ("DTC") P1326. Using the procedures published in TSB PI1802W/X and PI1803W/X, the subject vehicles were diagnosed and determined to require an engine replacement and are currently being held at dealers pending repair. As a result of additional field data collection and analysis, the initial diagnosis method has been updated to improve test result accuracy. Prior to performing an engine replacement on any of the VINs affected by this Service Action, the engine condition needs to be re-assessed utilizing an updated/expanded diagnostic process.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.