P1121 Land Rover Code - Accelerator Pedal Position Sensor Range/ Performance Problem
Quick Answer
The Accelerator Pedal Position (APP) sensor is located in plastic housing which is integral with the throttle pedal. Common causes include Faulty Accelerator Pedal Position (APP) Sensor, APP Sensor harness is open or shorted, APP Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1121 Land Rover indicates Accelerator Pedal Position Sensor Range/ Performance Problem.
- Common causes
- Common causes include Faulty Accelerator Pedal Position (APP) Sensor, APP Sensor harness is open or shorted, APP Sensor circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P1121 Land Rover Description
The sensor has a spigot which protrudes into the housing and provides the pivot point for the pedal mechanism. The spigot has a slot which allows for a pin, which is attached to the sensor potentiometers, to rotate through approximately 90°, which relates to pedal movement. The pedal is connected via a link to a drum, which engages with the sensor pin, changing the linear movement of the pedal into rotary movement of the drum. The drum has two steel cables attached to it. The cables are secured to two tension springs which are secured in the opposite end of the housing. The springs provide 'feel' on the pedal movement and require an effort from the driver similar to that of a cable controlled throttle. A detente mechanism is located at the forward end of the housing and is operated by a ball located on the drum. At near maximum throttle pedal movement, the ball contacts the detente mechanism. A spring in the mechanism is compressed and gives the driver the feeling of depressing a 'kickdown' switch when full pedal travel is achieved.
The APP sensor has two potentiometer tracks which each receive a 5V input voltage from the ECM. Track 1 provides an output of 0.5V with the pedal at rest and 2.0V at 100% full throttle. Track 2 provides an output of 0.5V with the pedal at rest and 4.5V at 100% full throttle. The signals from the two tracks are used by the ECM to determine fuelling for engine operation and also by the ECM and the EAT ECU to initiate a kickdown request for the automatic transmission.
The ECM monitors the outputs from each of the potentiometer tracks and can determine the position, rate of change and direction of movement of the throttle pedal. The 'closed throttle' position signal is used by the ECM to initiate idle speed control and also overrun fuel cut-off.
What are the Possible Causes of the DTC P1121 Land Rover?
- Faulty Accelerator Pedal Position (APP) Sensor
- APP Sensor harness is open or shorted
- APP Sensor circuit poor electrical connection
How to Fix the DTC P1121 Land Rover?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P1121 Land Rover code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P1121 Land Rover Code
1. What are the common symptoms of OBDII code P1121 in a Land Rover?
- Common symptoms include issues with acceleration, reduced engine power, stalling, and the vehicle going into limp mode.
2. What could cause the OBDII code P1121 in a Land Rover?
- The code P1121 is typically triggered by a faulty accelerator pedal position sensor, wiring issues, or a problematic throttle body.
3. How can I diagnose the cause of the OBDII code P1121 in my Land Rover?
- To diagnose the issue, you can use an OBDII scanner to read the code, visually inspect the accelerator pedal position sensor and related wiring, and perform a throttle body inspection.
4. Can I still drive my Land Rover with the OBDII code P1121 present?
- It is not recommended to drive the vehicle with the code P1121 present, as it can lead to further damage and safety concerns due to potential acceleration issues.
5. How can I repair the OBDII code P1121 in my Land Rover?
- Repairing the code P1121 may involve replacing the accelerator pedal position sensor, repairing faulty wiring, or cleaning/replacing the throttle body.
6. Will resetting the OBDII code P1121 in my Land Rover make it go away permanently?
- Resetting the code may temporarily clear the warning light, but if the underlying issue is not fixed, the code is likely to return.
7. Is it safe to continue driving my Land Rover if the OBDII code P1121 comes and goes intermittently?
- It is best to address the issue promptly, as intermittent occurrences of the code can still indicate potential problems with the accelerator pedal position sensor or related components.
8. How much does it typically cost to repair the OBDII code P1121 in a Land Rover?
- The cost of repairing the code P1121 can vary depending on the specific issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.
9. Can a DIY enthusiast fix the OBDII code P1121 in a Land Rover, or should it be done by a professional mechanic?
- Depending on your experience and tools available, some DIY enthusiasts may be able to tackle the repair themselves. However, for complex issues or if unsure, it is recommended to seek the help of a professional mechanic.
10. How long does it typically take to repair the OBDII code P1121 in a Land Rover?
- The repair time can vary depending on the exact cause of the code and the extent of the repair needed. It may take a few hours to a full day to diagnose and fix the issue.
Discuss the causes and fixes for P1121 Land Rover OBDII Code
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My 2003 Land Rover Freelander's accelerator pedal position sensor's causing issues (at least, so it seems).
When I hook it up to the diagnostic machine, track 1 reads as it should. Starts with nothing, and as I move the pedal, it climbs accordingly. However, track 2 is constantly sending random data. The graph screen is jumping all over the place. I'm fairly dismayed at the incredible lack of information for an 03' LR Freelander's accelerator potentiometer and how to fix it. Would you happen to know any online resources? I mean, getting the pedal assembly out alone has turned into an insane venture. I've NEVER seen a dash assembly so impossible to get through. All I want to do is pull the pedal assembly out. It's been 2 hours and I only have half of the dash assembly taken apart, Seriously - what were the engineers thinking that put this thing together? Anyway - if you know of any resources I'd be ever grateful.
Thanks. -
oh - also - I can't seem to find ANYBODY who actually sells the pedal position sensor. When I search autozone, O'Reilly, Amazon, even ebay. I can't find the part. Autozone keeps thinking I'm asking for the TPS (as does youtube, google, oreilly, and nearly every other search I've tried.).
The only place that even comes close is ebay which sells the entire pedal assembly, but I only want the potentiometer. Why is this problem so insane and why doesn't anybody carry the part, and why do all these sites keep thinking I'm looking for the TPS? Grah! -
Unfortunately, I couldn't find anything either, even our program to search all OEM parts. My guess is the accelerator pedal position sensor was never sold separately by anybody (like many other manufacturers).
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