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DTC codes / GM codes / P1573

P1573 · GMPCM EBTCM Serial Data Circuit

P1573 on GM vehicles indicates that the Powertrain Control Module (PCM) has lost or corrupted the serial data communication link with the Electronic Brake and Traction Control Module (EBTCM), often referred to as the ABS controller. The PCM monitors a dedicated serial data circuit between the two modules and sets this code when the expected messages are missing, intermittent, or invalid, which can disable traction control and affect brake performance.

SystemPowertrain
Code typeGM specific
SeverityMedium
Fix difficultyProfessional
AreaVehicle speed, idle control and auxiliary inputs

Symptoms you may notice

  • Anti-lock Brake System (ABS) warning light illuminated on the dashboard
  • Traction control or stability control warning light on, with the system disabled
  • Reduced engine power or limp mode in some GM models
  • Speedometer fluctuation or inaccurate readings
  • Often no symptoms besides the warning light, especially if the fault is intermittent
  • Brake pedal may feel different or ABS may not activate during hard braking

Common causes, most likely first

  1. Damaged or corroded wiring in the serial data circuit between the PCM and EBTCM
  2. Faulty EBTCM, often due to internal electronic failure or water intrusion
  3. Poor ground connection at the EBTCM or PCM mounting points
  4. Loose or corroded connectors at either module
  5. PCM software glitch or internal fault affecting serial communication
  6. Aftermarket accessories or improper electrical repairs interfering with the data bus
  7. Battery or charging system issues causing low voltage to the modules

How to diagnose and fix it

  1. Inspect the battery and charging system to ensure stable voltage above 12.4 volts with the engine off
  2. Check and clean the ground connections for the PCM and EBTCM, including the chassis and engine grounds
  3. Visually inspect the serial data wiring harness between the PCM and EBTCM for chafing, corrosion, or loose pins
  4. Use a scan tool to check for communication with the EBTCM and perform a bidirectional test if supported
  5. Measure resistance and continuity on the serial data circuit according to the factory wiring diagram
  6. If wiring and grounds are good, substitute a known-good EBTCM or PCM to isolate the faulty module
  7. Reprogram or replace the PCM or EBTCM as needed, then clear codes and verify communication

Serial Data Faults Often Misdiagnosed as ABS Failure

  • A common mistake is replacing the EBTCM immediately, but the fault often lies in a corroded ground or a chafed wire near the brake master cylinder area.
  • Intermittent P1573 codes can be caused by a weak battery or alternator, as voltage drops disrupt serial data communication before other symptoms appear.
  • Some GM vehicles use a dedicated serial data line between the PCM and EBTCM, while others communicate over the Class 2 bus; misdiagnosing the architecture leads to wrong repairs.
  • Aftermarket remote starters or alarm systems tapped into the data bus can corrupt the serial data signal and set this code without any hardware failure.
  • The code may set only when the vehicle is driven above a certain speed or when the ABS self-test runs, so a static check may not reveal the fault.

Can I keep driving with P1573?

You can usually drive the vehicle with P1573 set, but the ABS and traction control systems may be disabled, increasing stopping distances on slippery surfaces. Avoid hard braking or aggressive driving until the fault is repaired, and address the code promptly to restore full safety system function.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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