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P1921 Powertrain · manufacturer code
P1921 fault code: what 7 Ford owners reported
P1921 is a manufacturer-specific powertrain code (engine, transmission, fuel and emissions), so its exact definition belongs to the carmaker and is not in the generic OBD-II list. What it meant in practice is below, from 7 complaints owners filed with NHTSA. Updated November 3, 2026.
- 7owner reports
- 2car models
- 0mention a crash
- 0mention a fire
- 2015–2017model years
Which cars get code P1921?
Every model whose owners mentioned P1921 in a complaint, most reports first. Each year opens that car's full problem report. Popular models collect more reports because more of them are on the road.
Ford Transit
1 reportWhere does P1921 show up?
By brand
- Ford7
Component the owner filed it under
Is there a recall for P1921?
The others concern the component owners file this code under (Power Train) on the same cars; they may or may not relate to the code. Recall repairs are free; check your VIN at nhtsa.gov/recalls.
Power Train: Automatic Transmission Ford Motor Company (Ford) is recalling certain 2015-2017 F-150 vehicles. A loss of signal between the transmission range sensor and the powertrain control module can cause the transmission to unexpectedly downshift into second gear.
2016 Ford F-150, 2017 Ford F-150. Full risk and remedy on each car's report.
Power Train: Driveline: Driveshaft Ford Motor Company (Ford) is recalling certain 2015-2017 Transit vehicles. This recall includes all full-size Transit vehicles previously recalled under 17V-408 except ones that received mechanical universal joint (u-joint) as a remedy and any 156" or 178" wheelbase Chassis Cab and Cut-Away bodies…
2016 Ford Transit. Full risk and remedy on each car's report.
Power Train: Driveline: Driveshaft XL Hybrids, Inc (XL) is recalling certain 2015-2018 Ford Transit vehicles modified to be equipped with XL's electric hybrid system. The cardan (universal) joint on the front driveshaft may fail, possibly causing the front driveshaft to detach.
2016 Ford Transit. Full risk and remedy on each car's report.
Power Train: Automatic Transmission Ford Motor Company (Ford) is recalling certain 2017-2018 Ford F-150 and 2018 Ford Expedition and Mustang and Lincoln Navigator vehicles equipped with 10-speed automatic transmissions. A roll pin may not have been installed in the transmission, potentially causing a loss of the "Park" function.
2017 Ford F-150. Full risk and remedy on each car's report.
Power Train: Automatic Transmission: Lever And Linkage: Column Shift Ford Motor Company (Ford) is recalling certain 2017 F-150 vehicles equipped with ten-speed transmissions. The pin that attaches the transmission shift linkage to the transmission may come out, preventing the transmission from responding to movement of the shift lever.
2017 Ford F-150. Full risk and remedy on each car's report.
Power Train: Driveline: Driveshaft Ford Motor Company (Ford) is recalling all 2015-2017 Transit vehicles except 156" and 178" wheelbase Chassis Cab and Cut-Away bodies. In the affected vehicles, the flexible coupling connecting the transmission to the driveshaft may prematurely fail.
2016 Ford Transit. Full risk and remedy on each car's report.
Power Train: Automatic Transmission: Gear Position Indication (PRNDL) Ford Motor Company (Ford) is recalling certain 2017 F-150 trucks equipped with an eight-inch productivity screen. In these vehicles, the instrument cluster may lose power after the initial vehicle start-up in cold ambient temperatures. Several gauges, including the transmission gear position…
2017 Ford F-150. Full risk and remedy on each car's report.
What happened when owners saw P1921?
7 of the 7 reports, spread across the models above, as the owners wrote them. NHTSA removes names and VINs; long reports are trimmed. CarHooq has not verified individual claims.
Driving at 65mph in 5th gear, unexpected downshift into 3rd gear causing vehicle to loose power, immediate decline in speed by 20 mph and no acceleration. Vehicles behind me were forced to slam on brakes to avoid collision. Vehicle had check engine as well as wrench pop up on dashboard when downshift occurred. Took vehicle to Ford Dealership for diagnosis and repair. Error code p0706, p0707,p1702,p1921. Recommend to replace, Molded lead frame with main control, gaskets, transmission filter, fluid. Total cost for repair $2979.54.
Transmission Failed. It shifts when it should'nt on interstate downshifts and could cause a accident, took it to the dealership. Please read below Ford Dealership diagnostics. CUSTOMER STATES TRANSMISSION SHIFTING WHEN IT SHOULDNT”’TRANSMISSION SERVICE REQUIRED ERROR MESSAGE SHOWS UP ON DASH PLEASE intermitent light when acts up. Ford Dealership DIAGNOSE-- AND ADVISE. CAUSE: TRANSMISSION RANGE SENSOR/ LEADFRAME DIAGNOSTICS AND TESTING" VERIFIED CUSTOMERS CONCERN PULLED DTCS P0707 TRANSMISSION RANGE SENSOR CIRCUIT LOW, P01702 TRANSMISSION RANGE SENSOR CIRCUIT . . - INTERMITTENT, P1921 TRANSMISSION RANGE SIGNAL, P0706 TRANSMISSION RANGE SENSOR CIRCUIT RANGE/PERFORMANCE, P0707 TRANSMISSION…
Vehicle is experiencing delayed shifting and down-shifting at inappropriate times. Rear wheels will occassionally lock-up causingthe truck to slide sideways. Orange wrench light is on and the check engine light as well. It shows the following codes--P0706-00, P0707-00, P1702-00, AND P1921-00.
Very harsh down shifting, one incident happened at about 40mph but was already slowing down for a light so nothing catastrophic happened but if I was traveling at a higher speed a crash would’ve more than likely happened, and eventually threw codes: P0706, P0707, P1702, P1921 which is for the molded lead frame inside the transmission. Codes were pulled myself with my own devices and according to research all code descriptions are things that are faulty on the molded lead frame assembly
2015 Ford F150 - 85,000 miles. While driving at highway speeds vehicle suddenly locked the tires and began to slide out of control. PRNDL display went black and wrench warning light illuminated on dash. Car behind me nearly rear-ended due to rapid deceleration without brake lights. I was able to steer to the shoulder to avoid an accident. After shutting off vehicle and restarting, vehicle acted normally. Wrench indicator remained illuminated. Took vehicle to local ford dealership where multiple PCM codes were found: P06E9, P0707, P1702, P1921. Dealer Service was able to reproduce issue; slight movement/wiggle to shifter caused transmission range sensor to "go erratic". Technician recommended…
2016 Ford 150 6R80 auto transmission. I was driving downhill on a paved county road coming to a stop. Pulled onto 2 lane highway, accelerated, then tranmission hard down shifted unexpectedly to limp mode. Engine ran in high idle and would not shift up. Wrench light lit up. I'm lucky nobody was coming up behind me or I wouldn't be here to submit this! The dealer was relatively close, so I went directly, and slowly, there. Dealer pulled codes P0706, P0707, P0720, P0722, P1921, P1702, P0722. They confirmed it was a faulty molded lead frame. Dealer was not able to get transmission to shift, and then it wouldn't start at all. $1300 repair. This happened July 6. Part is not available till Aug…
Shift indicator light will flash and go off. Check engine light and wrench light comes on for coded P0706, P0707, P1702, P1921. U0401. Needed range sensor. Shifted when it wanted to and quit altogether then start back up. Had range sensor replaced.
P1921: questions drivers ask
What does code P1921 mean?
P1921 is a manufacturer-specific powertrain code (engine, transmission, fuel and emissions), so its exact definition depends on the carmaker and is not in the generic OBD-II list. 7 owners reported it to NHTSA, most often for the Ford F-150 (6), Ford Transit (1); their reports describe what happened.
Which cars get code P1921 most often?
In NHTSA owner complaints, P1921 is mentioned most for the Ford F-150 (6), Ford Transit (1), across 2 models and model years 2015 to 2017. Popular models collect more reports because more of them are on the road.
Is there a recall for code P1921?
No NHTSA recall text names P1921 directly. 7 recalls on the cars that report this code concern the same component owners name most (Power Train); they may or may not relate to the code. Check your VIN at nhtsa.gov/recalls.
What should I do if my car shows P1921?
Write down when the code appeared and what the car did (warning lights, loss of power, noises, speed, weather). Check your VIN for open recalls at nhtsa.gov/recalls, ask a dealer or independent workshop to read the stored freeze-frame data before anyone clears the code, and keep the repair order. If the car loses power in traffic, stop driving it. CarHooq does not diagnose: these are owner reports and official recall notices, not repair advice.
How this page was made
CarHooq read the text of every owner complaint filed with NHTSA for 19 US and European brands (model years 2012 onwards) and picked out the diagnostic trouble codes owners wrote down. This page lists every mention of P1921. Manufacturer codes have no public standard definition, so CarHooq shows only what owners reported. Nothing here is a diagnosis. Data: NHTSA Office of Defects Investigation (public domain), retrieved November 3, 2026. How CarHooq reports are made.
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