P2100 on 2020 Jeep Compass: Electronic Throttle Control Circuit Causes and Fixes

What's Unique About the 2020-2020 Jeep COMPASS

For the 2020 Jeep Compass with the 2.4L Tigershark engine, this code is specifically addressed by Technical Service Bulletin 09-003-20 REV. C. Unlike a simple software glitch, this TSB involves inspecting the throttle body's Julian manufacturing date and potentially replacing the entire unit, suggesting a batch of defective parts from the factory. Owners unaware of this may unnecessarily replace a throttle body that is not part of the defective batch or fail to have a potentially faulty one replaced under warranty. This engine and the "small wide 4x4 architecture" platform are shared with other vehicles like the Jeep Renegade and Fiat 500X, which also report similar throttle-related issues.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light is on
• Electronic Throttle Control (ETC) warning light (a red lightning bolt symbol) is illuminated or flashing.
• Vehicle enters "limp home mode," with drastically reduced engine power and limited RPM.
• Poor, delayed, or no throttle response (unresponsive gas pedal).
• Engine may hesitate, stall, or idle roughly.
• In some cases, the vehicle may not start.

Most Likely Causes

1. Defective Throttle Body (per TSB) 🔴 High Probability Manufacturer TSB #09-003-20 REV. C specifically calls for inspecting the Julian date on the throttle body of 2020 models and possibly replacing it, indicating a known manufacturing defect in a specific batch of parts. The affected Julian dates are stamped on the unit and are between 2419 and 2549.
   How to confirm: A Jeep dealership must check the vehicle's VIN against the RRT (Rapid Response Transmittal) 20-012 list for this TSB. They will then physically inspect the throttle body for a Julian date between 2419-2549 or for an “S1” or “S2” mark indicating inspection status.
   Typical fix: Replacement of the throttle body assembly if it's from the faulty batch, followed by an ETC relearn procedure. This is often covered under warranty.
   Est. part cost: $0 (if under warranty/TSB)
2. Faulty Electronic Throttle Body Assembly 🟡 Medium Probability Outside of the specific TSB, the internal electric motor or plastic gears can fail, causing slipping or an open circuit. This is a common failure point on many modern drive-by-wire systems. A clicking or grinding noise from the throttle body when the ignition is turned on is a strong indicator of this failure.
   How to confirm: After ruling out the TSB, a mechanic will test the wiring. If wiring is good, the throttle body is the likely culprit. A clicking or grinding noise from the throttle body when the ignition is cycled can indicate stripped internal gears. Resistance of the throttle body motor can also be checked to see if it's within spec.
   Typical fix: Replacement of the entire throttle body assembly. These are typically not serviceable and are replaced as a unit.
   Est. part cost: $150-$400
3. Wiring Harness or Connector Issue ⚪ Low Probability Vibrations and heat can cause wires to break or chafe, and the main connector to the throttle body can become loose or corroded, causing an open circuit.
   How to confirm: Visually inspect the wiring harness between the PCM and the throttle body for any signs of damage. Check that the red locking tab on the connector is secure. A multimeter is used to check for continuity and proper voltage at the throttle body connector pins according to the service manual.
   Typical fix: Repairing the damaged wire or cleaning/replacing the connector.
   Est. part cost: $10-$100

Rare But Worth Checking

• Powertrain Control Module (PCM) Failure: This is very rare and should only be considered after all other possibilities, including the TSB, wiring, and the throttle body itself, have been ruled out.
• Faulty Accelerator Pedal Position (APP) Sensor: While less common for a P2100 'circuit open' code, a failing pedal sensor can sometimes cause erratic throttle behavior and trigger related codes.

Diagnosis Steps

1. Scan the vehicle for all stored trouble codes. Note any other codes that appear with P2100.
2. Check for applicable Technical Service Bulletins (TSBs). For a 2020 Compass, TSB #09-003-20 REV. C is the primary concern.
3. Contact a Jeep dealership to verify if the vehicle's VIN is on the list for RRT 20-012, which is associated with the TSB.
4. If the TSB is applicable, follow its procedure: Inspect the Julian date on the throttle body. If it's from the defective batch (stamped between 2419 - 2549), replace it. If not, or if the TSB has been performed (indicated by a mark like "S2"), proceed with further diagnosis.
5. If the TSB does not apply or the code returns, perform a thorough visual inspection of the wiring harness and connector at the electronic throttle body. Look for damage, corrosion, or loose pins. Ensure the connector's red locking tab is fully engaged.
6. Using a multimeter and a wiring diagram, verify that the throttle body is receiving the correct voltage, ground, and command signals from the PCM. The Throttle Position Sensor (TPS) signal should sweep smoothly from ~0.5V (closed) to ~4.5V (wide open).
7. If wiring and signals are confirmed to be good, the electronic throttle body assembly is the most likely cause of the fault and should be replaced.
8. After replacement, perform a throttle relearn procedure. This can sometimes be done manually (e.g., turning the key to 'On', slowly pressing and releasing the accelerator pedal, then turning off before starting) or may require a diagnostic scan tool like wiTECH to initiate the ETC Relearn function.

Parts You'll Likely Need

• Electronic Throttle Body Assembly (OEM #04891970AD) — This is the most common hardware failure for code P2100 after TSB-related issues have been ruled out. The internal motor or gears fail, creating the 'open circuit' condition. This part number supersedes 4891970AB and 4891970AC.
  Trusted brands: Mopar, Dorman, Hitachi, Standard Motor Products
  OEM price range: $375-$545
  Aftermarket price range: $150-$250

Related Codes That Often Appear With This One

• P2101 — This code indicates a performance/range issue with the throttle actuator motor, which is often logged alongside circuit fault codes like P2100.
• P2110 — This code indicates the throttle actuator control system is forced to a limited RPM, a direct result of the fault detected by P2100 and the system entering 'limp mode'.
• P2107 — This code for 'Throttle Actuator Control Module Processor' can appear alongside P2100, indicating a more complex failure within the throttle control system, as reported by owners.

Technical Service Bulletins (TSBs) & Recalls

• Bulletin #09-003-20 REV. C: This bulletin is critical. It supersedes previous versions and involves inspecting the Julian date on the throttle body for 2020 Jeep Compass and Cherokee models with the 2.4L engine. If the part is from a specific manufacturing period (2419-2549), it must be replaced. It also notes that an ETC relearn is required after replacement.

Platform-Specific Known Issues

• A known manufacturing defect can cause the Malfunction Indicator Lamp (MIL) to illuminate and set code P2100, as documented in TSB #09-003-20 REV. C. The fix is to inspect the throttle body's manufacturing date (Julian date between 2419-2549) and replace the unit if it falls within the defective batch.

Mechanic-Grade Diagnostic Values

• Throttle Position Sensor (TPS) Voltage at Closed Throttle — expected: Approximately 0.5V to 0.7V. Failure: Voltage is significantly higher (e.g., 0.9V+) or 0V.
• Throttle Position Sensor (TPS) Voltage at Wide-Open Throttle (WOT) — expected: Approximately 4.5V to 5.0V. Failure: Voltage does not reach this range or has dead spots/spikes while opening.
• Live Data Scan Tool - Throttle Position Percentage — expected: Should increase smoothly from a low percentage at idle to a high percentage (e.g., 75-95%) at WOT as the pedal is pressed.. Failure: The percentage jumps erratically, drops out, or doesn't change with pedal movement.
• TSB-Specific Julian Date Inspection — expected: A four-digit number stamped on the throttle body housing.. Failure: The number is on or between 2419 and 2549, indicating it is part of the defective batch.

Scan Tool Commands That Help

• wiTECH (OEM Dealer Tool): Electronic Throttle Control (ETC) Learn — This function is required after replacing the throttle body assembly to calibrate the new part's position voltages with the PCM.
• High-End Aftermarket (e.g., Autel, iCarsoft): Throttle Body Diagnostics / Actuator Activation Test — To command the throttle plate to open and close, verifying if the motor is physically responding to commands from the scan tool. If it doesn't move but wiring is good, the throttle body is faulty.

Wiring & Ground Locations

• Throttle Body Connector — Plugged directly into the electronic throttle body assembly, which is mounted between the air intake hose and the engine's intake manifold.. This is the primary connection point for the throttle motor circuit. A loose connection, corrosion on the pins, or damaged wires at this connector will directly cause a P2100 open circuit code.
• G300 / G301 — On older Jeep platforms (like the WJ Grand Cherokee), these grounds are located under the front passenger (G300) and driver (G301) seats. While the exact location on a 2020 Compass may differ, checking major body and chassis grounds is crucial as a bad ground can cause various electrical faults.. The PCM and its related sensors require a stable ground reference. A poor or corroded main ground can cause floating voltages and intermittent circuit faults that mimic component failure.

Real Owner Repair Stories

• YouTube channel 'Jeep Compass throttle body fault and replacement' (2014 Jeep Compass (similar 2.4L engine and throttle body design)) — Flashing throttle warning light, check engine light, traction control light on. Clicking noise from throttle body on key-on. No throttle response, vehicle in limp mode.
  ❌ Tried (didn't work) Initial diagnosis confirmed accelerator pedal was sending a signal, but the throttle plate was not moving, ruling out the pedal sensor.
  ✅ What actually fixed it The entire throttle body assembly was replaced. The mechanic noted that after installing the new part, it was initially stuck and threw a 'throttle valve cannot close' code. A gentle manual push on the new butterfly plate freed it up, the code was cleared, and a throttle relearn was performed with a scan tool to complete the repair.

OEM Part Supersession History

• 4891970AB, 4891970AC → 04891970AD — Part revision and improvement by the manufacturer.
  Heads up: The latest part number, 04891970AD, is the correct replacement for the earlier versions and is specified for the 2020 Jeep Compass with the 2.4L engine.

Model Year Variations Within This Range

• 2020: A specific batch of throttle bodies manufactured within a certain period (Julian dates 2419-2549) are known to be defective, as per TSB 09-003-20 REV. C. Vehicles built outside of this component window are less likely to experience this specific failure, though standard throttle body failure can still occur.