{"product_id":"p21-1019-103-genuine-paccar®-turnstalk-speed-control-module","title":"P21-1019-103 | Genuine Paccar® Turnstalk Speed Control Module","description":"\u003cp\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003cbr\u003eA Turnstalk Speed Control Module\u003cstrong\u003e P21-1019-103\u003c\/strong\u003e is basically the part of a vehicle’s cruise control system that’s built into (or directly connected to) the turn signal stalk on the steering column. Turnstalk Speed Control Module For \u003cspan style=\"font-size: 0.875rem;\"\u003eKenworth\/Peterbilt Trucks, Peterbilt 320, \u003c\/span\u003e\u003cspan style=\"font-size: 0.875rem;\"\u003ePeterbilt 388\u003c\/span\u003e\u003cspan style=\"font-size: 0.875rem;\"\u003e, \u003c\/span\u003e\u003cspan style=\"font-size: 0.875rem;\"\u003ePeterbilt 389\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003cbr\u003ePart Number\u003c\/strong\u003e: P21-1019-103, P211019103\u003cbr\u003e\u003cstrong\u003eCondition\u003c\/strong\u003e\u003cspan\u003e: New\u003c\/span\u003e\u003cbr\u003e\u003cstrong\u003eManufacture\/Brand\u003c\/strong\u003e\u003cspan\u003e: Paccar\u003cbr\u003e\u003cbr\u003e\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003cstrong data-start=\"160\" data-end=\"176\"\u003e\u003c\/strong\u003e\u003cstrong\u003eFits P21-1019-103\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003eFor \u003cspan style=\"font-size: 0.875rem;\"\u003eKenworth\/Peterbilt Trucks, Peterbilt 320, \u003c\/span\u003e\u003cspan style=\"font-size: 0.875rem;\"\u003ePeterbilt 388\u003c\/span\u003e\u003cspan style=\"font-size: 0.875rem;\"\u003e , \u003c\/span\u003e\u003cspan style=\"font-size: 0.875rem;\"\u003ePeterbilt 389\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cstrong data-start=\"585\" data-end=\"597\"\u003e\u003c\/strong\u003e\u003cstrong data-start=\"585\" data-end=\"597\"\u003ePurpose of using P21-1019-103:\u003cbr\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable width=\"100%\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp data-section-id=\"1qt990x\" data-start=\"178\" data-end=\"197\"\u003e\u003cstrong\u003e1. Driver input\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"198\" data-end=\"248\"\u003eYou move the turnstalk lever or press its buttons:\u003c\/p\u003e\n\u003cul data-start=\"249\" data-end=\"285\"\u003e\n\u003cli data-section-id=\"1o4ryi\" data-start=\"249\" data-end=\"254\"\u003eSet\u003c\/li\u003e\n\u003cli data-section-id=\"724qq9\" data-start=\"255\" data-end=\"263\"\u003eResume\u003c\/li\u003e\n\u003cli data-section-id=\"1fox1j\" data-start=\"264\" data-end=\"276\"\u003eAccelerate\u003c\/li\u003e\n\u003cli data-section-id=\"1uxxklq\" data-start=\"277\" data-end=\"285\"\u003eCancel\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-section-id=\"1b50zkb\" data-start=\"287\" data-end=\"310\"\u003e\u003cstrong\u003e2. Signal detection\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"311\" data-end=\"391\"\u003eThe module inside (or attached to) the stalk detects which command you selected.\u003c\/p\u003e\n\u003cp data-section-id=\"98937y\" data-start=\"393\" data-end=\"417\"\u003e\u003cstrong\u003e3. Signal processing\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"418\" data-end=\"494\"\u003eIt converts that input into an electrical signal the vehicle can understand.\u003c\/p\u003e\n\u003cp data-section-id=\"19em178\" data-start=\"496\" data-end=\"523\"\u003e\u003cstrong\u003e4. Communication to ECU\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"524\" data-end=\"612\"\u003eThe module sends that signal to the vehicle’s main control system (engine control unit).\u003c\/p\u003e\n\u003cp data-section-id=\"fsk4df\" data-start=\"614\" data-end=\"641\"\u003e\u003cstrong\u003e5. Speed control action\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"642\" data-end=\"658\"\u003eThe ECU adjusts:\u003c\/p\u003e\n\u003cul data-start=\"659\" data-end=\"722\"\u003e\n\u003cli data-section-id=\"5i9yhm\" data-start=\"659\" data-end=\"688\"\u003eThrottle (or fuel delivery)\u003c\/li\u003e\n\u003cli data-section-id=\"c16wf4\" data-start=\"689\" data-end=\"722\"\u003eSometimes transmission behavior\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"724\" data-end=\"766\"\u003eto maintain or change the vehicle’s speed.\u003c\/p\u003e\n\u003cp data-section-id=\"dz5s4a\" data-start=\"768\" data-end=\"794\"\u003e\u003cstrong\u003e6. Continuous feedback\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"795\" data-end=\"894\"\u003eThe system constantly checks vehicle speed and keeps adjusting automatically to hold the set speed.\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSigns of a Bad Turnstalk Speed Control Module P21-1019-103:\u003cbr\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable width=\"100%\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e \n\u003cp data-start=\"189\" data-end=\"271\"\u003e\u003cstrong data-start=\"189\" data-end=\"224\"\u003e1. Cruise control won’t turn on\u003c\/strong\u003e\u003cbr data-start=\"224\" data-end=\"227\"\u003eYou press “ON” or “SET” and nothing happens.\u003c\/p\u003e\n\u003cp data-start=\"273\" data-end=\"305\"\u003e\u003cstrong data-start=\"273\" data-end=\"303\"\u003e2. Can’t set or hold speed\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"306\" data-end=\"373\"\u003e\n\u003cli data-section-id=\"1ithd7c\" data-start=\"306\" data-end=\"329\"\u003eSpeed won’t lock in\u003c\/li\u003e\n\u003cli data-section-id=\"aqzz3z\" data-start=\"330\" data-end=\"373\"\u003eCruise drops out randomly while driving\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"375\" data-end=\"418\"\u003e\u003cstrong data-start=\"375\" data-end=\"416\"\u003e3. Buttons on the stalk don’t respond\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"419\" data-end=\"518\"\u003e\n\u003cli data-section-id=\"76o44m\" data-start=\"419\" data-end=\"463\"\u003e“Resume,” “Coast,” or “Accel” don’t work\u003c\/li\u003e\n\u003cli data-section-id=\"s0ynlp\" data-start=\"464\" data-end=\"518\"\u003eOnly some functions work (partial failure is common)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"520\" data-end=\"625\"\u003e\u003cstrong data-start=\"520\" data-end=\"549\"\u003e4. Intermittent operation\u003c\/strong\u003e\u003cbr data-start=\"549\" data-end=\"552\"\u003eWorks sometimes, then suddenly stops—often due to worn internal contacts.\u003c\/p\u003e\n\u003cp data-start=\"627\" data-end=\"701\"\u003e\u003cstrong data-start=\"627\" data-end=\"661\"\u003e5. Cruise cancels unexpectedly\u003c\/strong\u003e\u003cbr data-start=\"661\" data-end=\"664\"\u003eEven without braking or driver input.\u003c\/p\u003e\n\u003cp data-start=\"734\" data-end=\"777\"\u003e\u003cstrong data-start=\"734\" data-end=\"762\"\u003e6. Erratic speed changes\u003c\/strong\u003e\u003cbr data-start=\"762\" data-end=\"765\"\u003eVehicle may:\u003c\/p\u003e\n\u003cul data-start=\"778\" data-end=\"830\"\u003e\n\u003cli data-section-id=\"4keb2e\" data-start=\"778\" data-end=\"796\"\u003eSurge slightly\u003c\/li\u003e\n\u003cli data-section-id=\"91j12p\" data-start=\"797\" data-end=\"830\"\u003eFail to maintain steady speed\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"832\" data-end=\"919\"\u003e\u003cstrong data-start=\"832\" data-end=\"867\"\u003e7. Other stalk functions act up\u003c\/strong\u003e\u003cbr data-start=\"867\" data-end=\"870\"\u003eSince it’s integrated with the turn signal lever:\u003c\/p\u003e\n\u003cul data-start=\"920\" data-end=\"983\"\u003e\n\u003cli data-section-id=\"1wnbcgi\" data-start=\"920\" data-end=\"983\"\u003eTurn signals or high beams may behave oddly (in some designs)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp data-end=\"476\" data-start=\"97\"\u003e\u003cstrong data-end=\"151\" data-start=\"97\"\u003e\u003cbr\u003eAbout the Manufacturer – Paccar:\u003c\/strong\u003e\u003cbr data-end=\"154\" data-start=\"151\"\u003e\u003c\/p\u003e\n\u003cp data-start=\"96\" data-end=\"400\"\u003e\u003cstrong data-start=\"96\" data-end=\"110\"\u003ePACCAR Inc\u003c\/strong\u003e is a global technology leader in the design, manufacture, and customer support of premium light-, medium-, and heavy-duty trucks. Founded in 1905 and headquartered in Bellevue, Washington, PACCAR is best known for its world-class truck brands: Kenworth, Peterbilt, and DAF.\u003cbr\u003ePACCAR’s trucks are recognized for their durability, fuel efficiency, advanced engineering, and driver-focused technology. In addition to truck manufacturing, PACCAR also designs and builds diesel engines, and provides financial services, information technology, and aftermarket support to its global customer base.\u003c\/p\u003e","brand":"Paccar","offers":[{"title":"Default Title","offer_id":50747889320183,"sku":"P21-1019-103","price":1169.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/7080\/3959\/files\/2026-04-30213018.png?v=1777573920","url":"https:\/\/forcetruckparts.com\/products\/p21-1019-103-genuine-paccar%c2%ae-turnstalk-speed-control-module","provider":"Force Truck Parts","version":"1.0","type":"link"}