P0573 on 2015 Dodge Challenger: Brake Switch Circuit High Causes and Fixes

What's Unique About the 2015-2015 Dodge CHALLENGER

For the 2015 Dodge Challenger and its platform mates (like the Charger and Chrysler 300), P0573 is unique because it's frequently caused by a software issue, not a hardware failure. Dodge issued Technical Service Bulletins (TSBs) acknowledging that this code can be set erroneously, sometimes in conjunction with other codes like U0140 and P0300. Therefore, a crucial first step, which is different from many other vehicles, is to check if a PCM software update is available before replacing any parts.

Diagnostic Flowchart

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

Symptoms You May Notice

• Cruise control is inoperative or will not engage.
• Adaptive Cruise Control (ACC) is inoperative (if equipped).
• Check Engine Light is illuminated.
• Brake lights may be stuck on or not work at all.
• ABS or Electronic Stability Control (ESC) warning lights may appear on the dash.
• Difficulty shifting the transmission out of the 'Park' position.

Most Likely Causes

1. Powertrain Control Module (PCM) Software Glitch 🔴 High Probability Manufacturer TSBs #18-070-16 and #18-011-15 REV. A specifically confirm that this code can be set erroneously on 2015 models due to software issues that require a PCM re-flash. This is a well-documented issue for the entire Charger/Challenger/300 platform.
   How to confirm: Contact a Dodge dealership with your vehicle's VIN to see if it is covered by a relevant TSB for a PCM software update. A dealer can check the software version using a wiTECH scan tool.
   Typical fix: The dealership will re-flash the PCM with the latest software calibration. This procedure requires a battery charger to maintain stable voltage and takes approximately 5 minutes for the download portion.
   Est. part cost: $0-$200 (depending on warranty/dealer policy)
2. Faulty Brake Light Switch 🔴 High Probability The brake light switch is a high-use electromechanical component that wears out. Its location near the pedal makes it susceptible to being kicked or damaged, leading to internal shorts or open circuits.
   How to confirm: Use a scan tool to monitor the 'Brake Pedal Status' in live data; it should change from 'Released' to 'Pressed' when the pedal is depressed. Alternatively, use a multimeter to test for continuity and correct voltage changes as the switch plunger is operated.
   Typical fix: Replace the brake light switch located on the brake pedal arm. This involves disconnecting the harness and twisting the switch to remove it from its bracket.
   Est. part cost: $20-$60
3. Wiring or Connector Issue ⚪ Low Probability The wiring harness near the brake pedal can be kicked, stressed, or chafed against sharp edges under the dash, leading to a short to voltage or a loose connection at the switch.
   How to confirm: Visually inspect the wiring harness and connector for damage, corrosion, or loose pins. Check for a short to voltage in the signal circuit using a multimeter.
   Typical fix: Repair the damaged section of the wiring harness or clean/re-seat the connector.
   Est. part cost: $5-$25
4. Blown Fuse ⚪ Low Probability
   How to confirm: Locate and inspect the fuse(s) related to the brake light and cruise control circuits in the vehicle's fuse box. For the 2015 Challenger, fuses F6 and F7 in the rear fuse box (in the trunk) are for the left and right stop lamps. The fuse location can be found in the owner's manual.
   Typical fix: Replace the blown fuse with a new one of the same amperage.
   Est. part cost: $1-$5

Rare But Worth Checking

• Aftermarket LED Brake Lights: If you have recently installed aftermarket LED bulbs, they may not have the correct resistance, causing the PCM to see an incorrect voltage and trigger the code. Installing a load resistor in the circuit can often fix this issue by mimicking the power draw of a standard incandescent bulb.
• Misadjusted Brake Light Switch: If the switch was recently replaced or disturbed, it might not be adjusted correctly, causing it to send a constant or incorrect signal. Some switches are self-adjusting upon installation, but improper installation can still lead to issues. A calibration may be required after replacement.

Diagnosis Steps

1. Check for other stored trouble codes. The presence of U0140 or P0300 strongly suggests the TSB-related software issue.
2. Verify brake light operation. Have an assistant confirm if the brake lights function correctly when the pedal is pressed and released. Note if they are stuck on or off.
3. Check for relevant TSBs. This is a critical step for this vehicle. Contact a Dodge dealer with your VIN to determine if a PCM software update (per TSBs 18-070-16 or 18-011-15 REV. A) is available and has not been performed.
4. If no TSB applies or the software is up to date, visually inspect the brake light switch, its connector, and nearby wiring. Look for physical damage, corrosion, or a loose connection.
5. Test the brake switch using a scan tool. Observe the 'Brake Pedal Status' in live data while pressing and releasing the pedal. This is the most effective non-invasive test.
6. If a scan tool is unavailable, test the switch with a multimeter. Disconnect the switch and check for the correct changes in continuity/resistance as the plunger is operated, comparing readings to factory service manual specifications.
7. Inspect the relevant fuses for the brake and cruise control systems. Specifically, check fuses F6 and F7 in the trunk fuse box for the stop lamps.
8. If the switch, fuses, and software are all good, perform a continuity check on the wiring between the switch and the PCM to rule out a short or open circuit in the harness.

Parts You'll Likely Need

• Brake Light Switch (Stop Lamp Switch) (OEM #4671336AD) — This is the most common hardware failure for this code. It's a mechanical switch that wears out over time. The OEM part number 4671336AD supersedes previous versions 4671336, 4671336AB, and 4671336AC.
  Trusted brands: Mopar, Standard Motor Products (SMP), Dorman
  OEM price range: $40-$60
  Aftermarket price range: $15-$35

Related Codes That Often Appear With This One

• U0140 — As cited in TSBs #18-070-16 and #18-011-15 REV. A, this 'Lost Communication With Body Control Module' code can appear alongside P0573 as part of the same PCM software glitch. The TSBs are the prescribed fix for this combination of codes.
• P0300 — This 'Multiple Cylinder Misfire' code is also mentioned in TSBs #18-070-16 and #18-011-15 REV. A as being potentially triggered by the same PCM software issue that causes P0573, even though the systems are unrelated.

Technical Service Bulletins (TSBs) & Recalls

• 18-070-16: Notes that P0573 - Brake Switch 1 Stuck Off can be set along with U0140 and P0300, pointing to a software issue requiring a PCM re-flash for 2015 Challenger, Charger, and 300 models with the 3.6L engine.
• 18-011-15 REV. A: Also lists P0573 - Brake Switch 1 Stuck Off with U0140 and P0300 as a group of codes that may be stored in memory due to a software condition on vehicles built before Jan 24, 2015.

Platform-Specific Known Issues

• TSB #18-070-16 and TSB #18-011-15 REV. A both indicate that for some 2015 Challengers, the P0573 code can be set erroneously along with U0140 and P0300. The prescribed fix is a PCM software update, not necessarily a part replacement.
• TSB 18-011-15 REV. A specifically applies to vehicles built on or before January 24, 2015, and equipped with the 3.6L V6 engine.

Mechanic-Grade Diagnostic Values

• Brake Switch 'A' Signal Circuit Voltage (Pedal Released) — expected: Near 12V (Battery Voltage). Failure: A reading of 0V or significantly below battery voltage indicates a potential open or short to ground. A reading significantly above battery voltage (e.g., >13V) can indicate a short or regulator issue.
• Brake Switch 'A' Signal Circuit Voltage (Pedal Depressed) — expected: Near 0V. Failure: If the voltage does not drop to near 0V when the pedal is pressed, the switch is likely faulty or misadjusted.
• Ground Wire Resistance — expected: < 1.0 Ohm. Failure: A resistance reading higher than 1.0 Ohm between a known good ground (like the negative battery terminal) and the component's ground wire indicates a poor ground connection, which can cause various electrical issues.

Scan Tool Commands That Help

• wiTECH or equivalent advanced scan tool: Live Data Monitoring: 'Brake Pedal Status' — This is the primary non-invasive test. While observing live data, press and release the brake pedal. The status should toggle cleanly between 'Pressed' and 'Released'. If it doesn't change, or is erratic, it points to a problem with the switch, wiring, or adjustment.
• wiTECH or equivalent advanced scan tool: Live Data Monitoring: 'Brake Pedal Travel Sensor' — On some models, in addition to the on/off status, the scan tool can show how far the pedal is traveling. This can help diagnose a misadjusted switch or a mechanical issue with the pedal assembly. The value should increase smoothly as the pedal is depressed.
• wiTECH: PCM Flash/Reprogram — This is the specific fix called for by TSBs #18-070-16 and #18-011-15 REV. A when P0573 is present, especially with U0140 and/or P0300. It should be performed if the vehicle's software is outdated and other hardware tests pass.

Wiring & Ground Locations

• Stop Lamp Fuses — In the rear fuse box, located in the trunk next to the battery.. Fuses F6 (left stop lamp) and F7 (right stop lamp) directly protect the brake light circuits. While a single blown fuse might not set P0573, checking them is a fundamental step in diagnosing any brake light-related electrical issue.
• Brake Switch Connector — Attached to the brake light switch on the brake pedal arm, under the driver's side dashboard.. This is the primary connection point for the switch. It can be kicked or damaged, and the terminals can corrode or become loose, directly causing a 'Circuit High' fault. A visual and physical check of this connector is essential.
• Chassis Ground Point — A factory grounding point is located underneath the air intake box in the engine bay.. While not directly for the brake switch, this is a key ground for multiple systems controlled by the PCM. A corroded or loose ground here can introduce stray voltage and unpredictable electrical behavior, potentially contributing to erroneous codes like P0573. Cleaning this ground is good preventative maintenance.

Real Owner Repair Stories

• CorvetteForum user (C6 Corvette (similar GM logic)) — P0573 code stored, cruise control inoperative.
  ❌ Tried (didn't work) Clearing the code (it returned).
  ✅ What actually fixed it The user was advised that the issue could be the brake position sensor, its calibration, the switch, or the ECM. The service manual information provided indicated the ECM sets the code when it detects an open or short to voltage on the signal circuit. This points towards a diagnostic path starting with the switch and wiring before suspecting the control module.

"I Checked Everything" — The Actual Cause

• For code P0573, the equivalent scenario is when the brake light switch and its wiring test perfectly with a multimeter (showing correct voltage changes and continuity). In this situation on a 2015 Challenger, the root cause is frequently an internal software error in the Powertrain Control Module (PCM). This is specifically addressed by Dodge's Technical Service Bulletins, which instruct technicians to reprogram the PCM to fix an 'Erroneous P0573' code.

OEM Part Supersession History

• 4671336, 4671336AB, 4671336AC → 4671336AD — Part revision and improvement by the manufacturer.
  Heads up: The newest part number, 4671336AD, is the correct and backward-compatible service part for this application. Using older stock is not recommended.

Model Year Variations Within This Range

• 2015 (built on or before Jan 24, 2015): Vehicles with the 3.6L engine built on or before this date are specifically called out in TSB #18-011-15 REV. A as being susceptible to the software glitch that causes P0573, U0140, and P0300 to set erroneously. Later builds may have received the updated software from the factory.