P2100 on 2021-2022 Jeep Gladiator: Electronic Throttle Control Motor Circuit Fixes

What's Unique About the 2021-2022 Jeep GLADIATOR

The 2021-2022 Jeep Gladiator (JT) platform, which shares many components with the Wrangler (JL), has a well-documented history of this specific issue. Multiple Technical Service Bulletins (TSBs) have been issued by Jeep to address P2100, pointing to a required software update for the Powertrain Control Module (PCM) rather than an immediate hardware failure. This suggests a sensitivity in the factory programming that can misinterpret data from the throttle control circuit under certain conditions, leading to the fault code. Forum discussions confirm that a PCM flash is the most common resolution reported by owners.

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
• Vehicle enters 'limp mode' with lack of power and reduced speed.
• Sudden loss of ability to accelerate, with the gas pedal becoming unresponsive.
• Blinking red electronic throttle control warning light.
• "Service Transmission” message may appear on the instrument cluster, even though the fault is with the engine's throttle system.
• Unstable or rough idle
• Traction control or start/stop system warning lights may also illuminate simultaneously.

Most Likely Causes

1. Powertrain Control Module (PCM) Software Glitch 🔴 High Probability → Shop Engine Control Module (ECM) Multiple TSBs (e.g., #18-071-22 REV. C, #18-006-26 REV.A) have been issued by Jeep specifically to update the PCM software to resolve this code, indicating it's a known firmware issue. These TSBs were also released as Rapid Service Updates (RSUs), indicating a proactive campaign by the manufacturer.
   How to confirm: A Jeep dealership or a qualified shop with a wiTECH scan tool can check the current software calibration level against the latest version specified in the TSBs. The TSB repair procedure explicitly involves checking if the latest software is installed before proceeding.
   Typical fix: Reprogramming (flashing) the PCM with the latest software version. This is often done during a routine service visit.
   Est. part cost: $0 (if covered under warranty or RSU campaign)
2. Faulty Electronic Throttle Body Assembly 🟡 Medium Probability → Shop Fuel Injection Throttle Body The internal motor of the throttle body can fail, creating the open circuit detected by the PCM. This is a common failure point for electronic throttle systems across many vehicle brands, and can occur on the Gladiator if the software fix is not the cause.
   How to confirm: After confirming the PCM software is up to date, a technician can use a scan tool to command the throttle body to open and close while monitoring its response. A multimeter can also be used to check for proper voltage and ground at the throttle body connector.
   Typical fix: Replacement of the entire throttle body assembly. The motor is typically not serviced separately.
   Est. part cost: $200-$400
3. Wiring Harness or Connector Issue ⚪ Low Probability
   How to confirm: Visually inspect the wiring harness leading to the throttle body for any signs of chafing, melting, or corrosion. Check that the connector is securely plugged in and the pins are clean and straight. A known issue on some related vehicles involves harnesses rubbing against frame members or engine components.
   Typical fix: Repairing the damaged section of the wire or cleaning/replacing the connector. In some cases, a damaged main harness may need significant repair or replacement.
   Est. part cost: $10-$50 for simple repairs, much higher for harness replacement

Rare But Worth Checking

• Failed Powertrain Control Module (PCM): → Shop Engine Control Module (ECM) This is a last resort. The PCM itself can fail, but this is uncommon and should only be considered after all other possibilities, including software and wiring, have been exhaustively ruled out.
• Blown Fuse or Faulty Relay: A blown fuse or a bad relay in the throttle control circuit can cause the open circuit condition. This should be checked as part of the basic electrical diagnosis before replacing major components.

Diagnosis Steps

1. Read all fault codes using a compatible OBD-II scanner. Note any other codes present, especially P2107.
2. Check for applicable Technical Service Bulletins (TSBs) for your vehicle's VIN. Specifically, look for TSBs #18-071-22 REV. C, #18-006-26 REV.A, and S2218000007.
3. If a TSB directs a PCM software update, have this performed by a dealership or qualified shop with a wiTECH tool. This is the most likely fix and should be the first step.
4. After the flash, clear all codes. The TSB procedure notes to test drive the vehicle to see if the code returns. If it does not, the repair is complete.
5. If the code returns, perform a thorough visual inspection of the wiring harness and connector at the electronic throttle body. Look for damage, loose connections, or corrosion.
6. Check fuses and relays related to the throttle control system.
7. Using a multimeter, check for correct voltage and ground at the throttle body connector according to the vehicle's service manual.
8. With a bi-directional scan tool, command the throttle plate to open and close to test the motor's functionality.
9. If the wiring and fuses are good and the motor fails the scan tool test, the throttle body assembly needs to be replaced.
10. After replacement, a throttle relearn procedure may be necessary using a scan tool.

Parts You'll Likely Need

• Electronic Throttle Body Assembly (OEM #68527921AA) — If a PCM software update does not resolve the issue, the internal motor of the throttle body has likely failed, requiring the replacement of the complete assembly. The OEM part number 68527921AA has been superseded by 68527921AB and then 68527921AC, indicating revisions to the part.
  Trusted brands: Mopar (OEM)
  OEM price range: $250-$400
  Aftermarket price range: $200-$300

Related Codes That Often Appear With This One

• P2107 — This code for 'Electronic Throttle Control Module Processor' is frequently cited alongside P2100 in Jeep TSBs, indicating an internal logic failure related to the throttle control system. A forum user with a 2022 Gladiator reported both codes appearing simultaneously during a sudden power loss event.
• P0132, P0138, P0152, P0158 — These O2 sensor circuit high codes are also mentioned in TSB #18-071-22 REV. C, suggesting the software issue causing P2100 may also affect how the PCM processes data from the oxygen sensors.

Technical Service Bulletins (TSBs) & Recalls

• 18-071-22 REV. C: Cites P2100 and P2107, recommending a PCM software update for 2022 models. Also mentions several O2 sensor codes.
• 18-006-26 REV.A: Mentions P2100 and a "Service Transmission" message for 2021 models.
• 1807122: Notes P2100 and P2107 related to a Malfunction Indicator Lamp (MIL). This was released as a Rapid Service Update (RSU).
• S2218000007: Describes a customer complaint of lack of power (limp-mode) associated with P2100.

Platform-Specific Known Issues

• Jeep has issued multiple Technical Service Bulletins related to code P2100 on this platform. TSB #18-071-22 REV. C and others indicate that a Powertrain Control Module (PCM) software update is the primary remedy.
• Owners have reported experiencing this code along with a sudden loss of power, forcing the vehicle into limp mode, which can be a significant safety concern if it occurs in traffic.
• Some TSBs also mention a "Service Transmission" message appearing in conjunction with this engine code, even though the root cause is in the electronic throttle system.
• A Gladiator owner on the forums described the event happening on their 2022 model with only 273 miles, highlighting that it can occur on very new vehicles.

Mechanic-Grade Diagnostic Values

• Electronic Throttle Body Connector Pinout (Typical 6-pin) — expected: Pin 1: ETC Motor Control (+), Pin 2: TP Sensor 1 Signal, Pin 3: TP Sensor 2 Signal, Pin 4: ETC Motor Control (-), Pin 5: 5V Reference, Pin 6: Sensor Ground.. Failure: Missing 5V on reference pin, no ground on ground pin, or open/short on motor control circuits.
• ETC Motor Resistance — expected: Between 2.5 and 25 ohms (measured at the PCM connector to include wiring).. Failure: Resistance outside of this range indicates a faulty motor or wiring.

Scan Tool Commands That Help

• wiTECH or equivalent professional scan tool: ETC Relearn / Throttle Follower Test — This function is mandatory after replacing the electronic throttle body assembly. It allows the PCM to learn the new throttle plate's fully open and fully closed positions. Failure to perform this can result in incorrect throttle response and new fault codes.
• wiTECH or equivalent bi-directional scan tool: Throttle Position Actuation Test — Used during diagnosis to verify if the throttle motor is responding to PCM commands. The technician can command the throttle plate to open to a specific percentage (e.g., 25%, 50%) and visually confirm its movement, helping to distinguish between a failed motor and a wiring issue.

Wiring & Ground Locations

• Electronic Throttle Body Connector — Directly on the electronic throttle body, located at the engine's air intake.. This is the primary connection point for the component at fault. Loose connection, corrosion, or damaged pins/wires here are a direct cause of an open circuit (P2100).
• G905A — On the right side of the engine block. It serves as a major grounding point for the powertrain harness.. A poor or corroded ground at this location can introduce electrical noise or voltage drops, potentially causing the PCM to misinterpret sensor data and trigger various faults, including P2100.

Real Owner Repair Stories

• JeepGladiatorForum.com user 'Rotatopotato' (2022 Jeep Gladiator Rubicon, 273 miles) — Sudden, complete loss of power while accelerating to merge into traffic. Multiple warning lights for traction control and start/stop illuminated.
  ✅ What actually fixed it The user pulled codes P2100 and P2107. Other forum members immediately pointed to the known TSB for a PCM software flash, which is the standard dealer repair for this exact scenario.
• JeepGladiatorForum.com user 'Jt-rubicon' (2022 Jeep Gladiator Rubicon (JTR)) — While passing a car, hit a rumble strip. The truck immediately went into limp mode with a blinking throttle light and threw code P2100.
  ✅ What actually fixed it The user took the vehicle to the dealer, who performed the TSB software update to fix the issue. This story highlights the software's sensitivity, where a physical jolt or vibration can be enough to trigger the fault condition.

When the Usual Fixes Don't Work

• While the vast majority of P2100 instances on the 2021-2022 Gladiator are resolved with the TSB software flash, there are documented cases in owner forums where this did not permanently fix the problem. In these instances, the code returned, and the ultimate fix was the replacement of the electronic throttle body assembly itself. This indicates that while the software glitch is the most probable cause, actual hardware failure of the throttle body motor can still occur and should be the next diagnostic step if the PCM flash is ineffective.

OEM Part Supersession History

• 68527921AA → 68527921AB, then 68527921AC — The multiple revisions suggest that the manufacturer made design or material changes to the electronic throttle body assembly, likely to improve its reliability and prevent the failures that can contribute to a P2100 code.

Model Year Variations Within This Range

• 2021 vs 2022: While the root cause (software) and fix (PCM flash) are the same for both model years, they are covered by different TSB numbers (e.g., #18-006-26 for 2021, #18-071-22 for 2022). A dealership must use the correct TSB for the specific model year to ensure the correct software is applied. There are no significant mechanical differences between the years related to this fault.