P2118 Code: Throttle Actuator Control Motor Current Range/Performance
The throttle motor is drawing more or less current than the PCM expects to hold the plate where it wants.
At a glance
Severity: Moderate
- Meaning
- Throttle Actuator Control Motor Current Range/Performance
- System
- Speed & Idle Control · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $80–$900
- DIY difficulty
- Moderate
The electronic throttle is opened and closed by a small DC motor driven through an H-bridge in the PCM, and the PCM keeps an eye on how much current that motor needs. Holding the plate against its return springs normally takes a modest, predictable current. P2118 sets when the measured current is out of line with the commanded position: too high usually means the motor is fighting something, such as a carbon ring gripping the plate, ice in the bore on a cold morning, worn gears or a partly shorted winding; too low points to high resistance in the motor circuit or a motor that's losing its brushes. Low system voltage and a poor PCM ground can also skew the reading. The PCM protects itself and the motor by switching to a spring-held limp position with a fixed fast idle.
Can I keep driving? Expect a raised idle and very limited power. Drive only to a safe place or a shop; if the car also stalls or surges, have it towed.
How to read P2118
- P Powertrain
- 2 Generic (SAE)
- 1 Fuel & air metering
- 18 Specific fault
Symptoms
- Check engine light, often with a wrench symbol or reduced-power message
- Throttle stuck at a fixed fast idle with little response to the pedal
- Fault appears on cold, damp mornings and disappears once the engine is warm
- Buzzing or whining from the throttle body with the key on
- Stalling when coming to a stop just before limp mode kicks in
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Carbon buildup or ice making the throttle plate bind in its bore
- Worn gear train or failing motor inside the throttle body
- Corroded motor terminals or high resistance in the motor wiring
- Low system voltage or poor PCM ground from a weak battery or charging fault
- PCM motor driver fault
- Plate rubbing after incorrect installation or a mismatched throttle body gasket
Diagnosis step by step
Check battery and charging voltage first
With the engine running, battery voltage should sit at about 13.5–14.7 V, and around 12.4–12.7 V engine off. Throttle motor codes often appear alongside low-voltage codes, and a weak battery or loose ground can make the motor current look wrong.
Tools: Multimeter, OBD-II scanner
Compare commanded and actual throttle with motor duty
In live data, look at desired throttle angle, actual angle and throttle motor duty cycle or current if your scan tool shows it. At warm idle the duty should be steady and modest. A duty that climbs high just to hold idle position suggests the plate is binding.
Tools: OBD-II scanner
Inspect the plate and bore
Key off, remove the intake duct and look for a black carbon ring around the plate edge or signs of moisture. Gently open the plate by hand with the key off: it should move smoothly and return to its rest position without gritty or notchy spots.
Tools: Flashlight
Measure the motor winding
Unplug the throttle body and measure resistance across the two motor pins. Most motors read only a few ohms; compare with your service data. Open circuit or near zero means a failed motor, and any continuity from a motor pin to the throttle body housing means an internal short.
Tools: Multimeter
Check the motor circuit wiring
With the connector unplugged and the PCM disconnected, check each motor wire end to end; it should measure well under 1 ohm. Inspect the throttle body connector terminals, because the motor terminals carry the most current and corrode first.
Tools: Multimeter, Flashlight
Clean or replace, then relearn
If carbon was the problem, clean the bore and plate with throttle body cleaner using a rag, with the key off. If the motor or gears are worn, replace the throttle body. Afterwards perform the throttle and idle relearn for your vehicle.
Tools: Soft brush, OBD-II scanner
Where the parts are
- 1Battery
- 2Alternator
- 3Engine computer (ECM)
- 4CAN bus
- 5Transmission
- 6Wheel speed sensor
- 7High-voltage battery
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Clean throttle body and perform relearn | Yes | $80–$200 |
| Replace electronic throttle body | Yes | $300–$900 |
| Repair throttle motor wiring or connector | No | $100–$300 |
| Replace weak battery or repair ground connections | Yes | $150–$350 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Ford
On Ford vehicles, throttle motor faults like P2118 typically light the orange wrench symbol and put the engine into a limited-power mode. Many cases are resolved with a new throttle body after wiring and battery checks.
Field data
| Dodge | 2 | Caliber, Journey |
|---|
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
P2118 illuminates the check engine light, which fails an OBD-II emissions inspection. After repair, let the vehicle complete a few normal drive cycles before the test.
Frequently asked questions
Why does P2118 only show up on cold mornings?
Moisture can condense and freeze around the throttle plate overnight, especially in engines with crankcase vapors routed near the throttle. The motor then strains to break the plate free, drawing too much current, and the code sets before the ice melts.
Is P2118 the same as P2101?
They're related but not identical. P2101 looks at whether the motor circuit and position response are in range, while P2118 focuses specifically on the current the motor draws. Both often point to the throttle body.
Will cleaning the throttle body fix it?
If carbon buildup was making the plate bind, yes. If the motor or gears inside are worn, cleaning only buys time. Recheck motor duty in live data after cleaning to see whether it has returned to normal.
Why would a bad battery cause a throttle motor code?
The PCM judges motor current against the voltage it's supplied with. A weak battery, poor ground or failing alternator can make an otherwise healthy motor look like it's out of range.