P0122 on Ford: How to Diagnose & Fix
Throttle/Pedal Position Sensor/Switch 'A' Circuit Low Input
2 Ford models · 2 documented issues · 1 critical · $100-$700 repair
P0122 on Ford by model: symptoms, diagnosis and fix
The CD3 Edge uses a Ford electronic throttle body (ETB) with an integrated throttle position sensor. Non-conductive deposits build up on the internal sensor contacts, so the PCM sees an implausible or drifting throttle plate position and drops the vehicle into failsafe/limp mode - the amber wrench warning lights up and engine output is cut to idle-ish power, often at highway speed with no warning. Owners describe it as the truck 'just quitting on me' merging or passing, sometimes clearing after a key cycle and then recurring more frequently. Cleaning the throttle bore does not fix it because the fault is on the electronic contacts inside the sealed unit, not carbon on the plate. Ford acknowledged the family-wide ETB problem with extended coverage programs on several models, and the failure is heavily represented in NHTSA complaints for the Edge.
Common Symptoms
- Amber wrench warning light on the cluster
- Sudden loss of power / limp mode at speed
- Engine will not rev past idle until restarted
- Surging or erratic idle
- Intermittent stall at stops
- Fault clears after key cycle then returns
How to Fix
Replace the throttle body assembly with an updated Motorcraft unit - the internal fault cannot be repaired or cleaned out. Note the part number differs between 2007-2010 and 2011-2014 Edges, so order by VIN. After installation the PCM must relearn throttle position (KAM reset plus an idle relearn drive cycle). Check that the ETB connector and harness pins are not corroded or spread before condemning a second throttle body. Verify whether your VIN falls under any remaining Ford extended service program coverage for ETB before paying out of pocket.
Sources for this issue (4)
- Throttle Body Service or Failure - 3.5L - Ford Edge Forumforum
- Throttle system limp mode issues HELP! - Ford Truck Enthusiasts Forumsforum
- Defective ETBs Are Sending Ford Vehicles into Limp Home Mode - FordProblemsarticle
- P0122 on 2007-2014 Ford Edge: Throttle Body Failure Causes, Symptoms, and Fixesarticle
Many owners of 2000-2011 Rangers report intermittent high idle, unstable idle, or stalling when coming to a stop, often traced to a failing throttle position sensor, dirty or failing idle air control valve, or both. The problem is especially common on older cable-throttle trucks where carbon buildup and sensor wear accumulate with age. Symptoms can be inconsistent, which leads to repeated parts swapping before the root cause is isolated.
Common Symptoms
- idle surging
- engine stalls at stoplights
- hanging idle between shifts
- hesitation off idle
- intermittent check engine light
How to Fix
Diagnosis should include live-data checks for TPS sweep irregularities, inspection for vacuum leaks, and cleaning/testing the IAC valve and throttle body. Repair usually involves replacing the faulty TPS or IAC, cleaning the throttle body, and resetting idle strategy if needed. If symptoms remain, inspect PCV hoses and intake gaskets for unmetered air leaks.
Sources for this issue (1)
P0122 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0122 mean on a Ford?
P0122 stands for "Throttle/Pedal Position Sensor/Switch 'A' Circuit Low Input." This generic code means the PCM detected a lower-than-expected voltage from the throttle position sensor (or accelerator pedal position sensor) 'A' circuit. This sensor tells the computer how far the throttle/pedal is open so it can manage fuel, timing, and on drive-by-wire systems the throttle itself. A low or lost signal can cause hesitation, surging, poor acceleration, stalling, or limp-home mode, so it should be diagnosed promptly. On Ford it is documented across 2 models: Edge, Ranger.
What are the most common causes of P0122?
The most common causes of P0122 are: Faulty throttle position sensor, Short to ground or open in the TPS signal circuit, Damaged or corroded TPS connector, Loss of reference voltage or bad ground to the sensor, Worn throttle body / TPS contacts, Chafed or pinched wiring harness, Faulty PCM (rare). The specific cause varies by vehicle.
How much does it cost to fix P0122 on a Ford?
Published repair estimates on Ford range from $100 to $700 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0122 on a different make?
View P0122 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.