P2103 Code: Throttle Actuator Control Motor Circuit High
The throttle motor circuit draws too much current – a short, a shorted motor or a plate that is jammed.
At a glance
Severity: Moderate
- Meaning
- Throttle Actuator Control Motor Circuit High
- System
- Speed & Idle Control · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $0–$1,600
- DIY difficulty
- Moderate
P2103 is the opposite of P2102: the PCM sees more current or a higher voltage in the throttle motor circuit than it should. Electrically that happens when the two motor wires touch each other, a motor wire rubs against a 12-volt feed, or the motor winding itself is partly shorted. Mechanically it happens when the plate can't turn – frozen in ice, jammed by carbon or blocked by a stripped gear – so the motor stalls and current climbs. To protect its driver the PCM shuts the motor off and the plate falls back to its spring-held limp position. If the code returns immediately after clearing, suspect a hard short; if it only appears on cold, damp mornings, suspect a binding plate.
Can I keep driving? The engine usually runs in limp mode with a fixed fast idle, so drive only as far as a safe place or a shop. If a fuse keeps blowing or the throttle body gets hot, stop resetting the code – a live short can damage the PCM.
How to read P2103
- P Powertrain
- 2 Generic (SAE)
- 1 Fuel & air metering
- 03 Specific fault
Symptoms
- Sudden limp mode with a fixed, raised idle
- Code returns the moment the ignition is switched on (hard short)
- Fault only on cold, wet mornings or after a car wash (binding plate)
- Throttle control fuse blown on vehicles that have one
- Engine hesitates or stalls when pulling away
- Check engine and electronic throttle warning lights
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Plate jammed or binding – ice, heavy carbon or a damaged gear – making the motor stall
- Motor winding partly shorted inside the throttle body
- Motor wires shorted together in a chafed or melted harness section
- Motor wire shorted to a battery-voltage circuit
- Stuck throttle motor relay or wrong fuse fitted (on makes with a relay)
- Shorted motor driver inside the PCM
Diagnosis step by step
Check whether the plate can move
Ignition off and key away from the car, remove the intake duct and gently ease the plate open. If it is frozen, glued by carbon or grinds, you have found the likely cause. In cold weather let the car warm up indoors before going further – never pry a frozen plate.
Tools: Flashlight, Gloves
Measure motor resistance for a short
At the throttle body, measure across the two motor pins. A value far below spec – often under about 0.5 Ω – indicates shorted windings; compare with a known-good unit if the manual gives no figure.
Tools: Multimeter
Test the harness for shorts
Unplug both ends and check between the two motor wires (should be open) and from each wire to ground. Then turn the ignition on and check each motor wire for voltage; any 12 V present with both ends unplugged means it is touching a live circuit.
Tools: Multimeter
Inspect the harness route
Follow the throttle body harness along the intake and valve cover. Look for melted insulation near the exhaust manifold or EGR tube, and for spots where the loom has worn through against a bracket.
Tools: Flashlight
Check fuse and relay
If the vehicle has a throttle control fuse, confirm it has the correct rating and hasn't been replaced with a larger one. A relay that stays energized with the key off also belongs on this list.
Tools: Multimeter
Verify the PCM driver after the repair
Once the short or jam is fixed, clear the code and watch commanded versus actual throttle during a key-on sweep and a road test. If P2103 comes straight back with a new throttle body and clean wiring, the PCM driver has likely been damaged.
Tools: OBD-II scanner
Where the parts are
- 1Ignition coil
- 2Spark plug
- 3Fuel injector
- 4Camshaft sensor
- 5Crankshaft sensor
- 6Engine computer (ECM)
- 7Intake manifold
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Thaw and dry throttle body, clean the bore | Yes | $0–$30 |
| Repair shorted or melted harness section | No | $120–$450 |
| Replace electronic throttle body and relearn | No | $350–$900 |
| Replace throttle motor relay | Yes | $30–$150 |
| Replace and program PCM | No | $700–$1,600 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Toyota
Toyota's P2103 reports excessive throttle motor current, which covers a short in the motor circuit and also a throttle valve that is physically stuck. Checking plate movement belongs at the start of the diagnosis.
Nissan
On Nissan the code refers to a short in the throttle control motor relay circuit, including a relay that stays switched on. The relay sits in the underhood IPDM E/R, so its control and output circuits are tested before the throttle body.
Field data
| Toyota | 2 | Corolla |
|---|
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
P2103 turns on the check engine light, which fails an OBD-based smog or emissions test. Fix the short first, then drive normally until the readiness monitors are complete.
Frequently asked questions
Can ice really set P2103?
Yes. Moisture from a car wash or from crankcase vapors can freeze the plate to its bore overnight. The motor tries to turn it, stalls, draws high current and the PCM logs a high-circuit fault. It usually clears once the engine bay warms up.
Why do I keep blowing the throttle fuse?
A fuse that blows repeatedly means real overcurrent – a shorted motor, a wire touching ground or another wire, or a jammed plate. Don't fit a bigger fuse; find the short, or you risk burning the harness or the PCM.
What's the difference between P2102 and P2103?
P2102 is too little current, which points toward resistance or low voltage. P2103 is too much current, which points toward shorts or a motor that can't turn. The tests are almost opposite, so the exact code matters.
Sources
- SAE J2012 – Diagnostic Trouble Code Definitions
- ISO 15031-6 – Road vehicles, diagnostic trouble code definitions (EOBD)
- Manufacturer public service information (cross-checked)
- NHTSA Complaints API
- Methodology: How We Build Code Pages · Data Sources We Use · Editorial Policy