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DTC codes / GM codes / P1652

P1652 · GMPowertrain Induced Chassis Pitch Output Circuit

P1652 on GM vehicles indicates that the powertrain control module (PCM) has detected an abnormal condition on the chassis pitch output circuit, which is used to send a signal to the electronic suspension or stability control system. The PCM monitors this circuit for expected voltage or continuity and sets the code when the signal is out of range, often due to a wiring fault or a failed module.

SystemPowertrain
Code typeGM specific
SeverityMedium
Fix difficultyIntermediate
AreaComputer and output circuits

Symptoms you may notice

  • The service engine soon or traction control warning light may illuminate on the dashboard.
  • Often no symptoms besides the warning light, especially if the fault is intermittent.
  • The ride may become firmer or softer than usual if the electronic suspension defaults to a fail-safe mode.
  • Stability or traction control systems may be disabled, reducing handling assistance in slippery conditions.
  • In some cases, a slight hesitation or poor performance may be noticed if the PCM limits torque to protect the drivetrain.

Common causes, most likely first

  1. Damaged or corroded wiring in the chassis pitch output circuit, such as an open or short to ground or power.
  2. Failed chassis pitch sensor (also known as a yaw or pitch sensor) that is not producing the correct signal.
  3. Faulty powertrain control module (PCM) output driver for the chassis pitch circuit.
  4. Poor electrical connection at the PCM or suspension control module connectors.
  5. A malfunctioning electronic suspension control module that is not communicating properly with the PCM.
  6. Aftermarket accessories or modifications that have tapped into the chassis pitch circuit and caused interference.

How to diagnose and fix it

  1. Inspect the wiring harness and connectors at the PCM and suspension control module for signs of damage, corrosion, or loose pins.
  2. Use a scan tool to check for other codes and view live data for the chassis pitch signal to see if it is stuck or erratic.
  3. Perform a voltage drop test on the chassis pitch output circuit to check for excessive resistance or an open circuit.
  4. Disconnect the suspension control module and check for the presence of the correct voltage signal from the PCM when commanded.
  5. If the signal is missing at the module but present at the PCM, repair the wiring between them.
  6. If the PCM is not outputting the correct signal, test the PCM with a known-good unit or perform a relearn procedure as required.
  7. After repairs, clear the codes and verify the circuit operates correctly with a test drive and live data monitoring.

Chassis Pitch Circuit Misdiagnosis Traps

  • A common mistake is to replace the chassis pitch sensor when the real problem is a chafed wire in the harness near the suspension components, so always inspect the wiring first.
  • The code can be set by a weak battery or charging system issue that causes the PCM to see implausible voltage on the circuit, so check battery and grounds before condemning modules.
  • On some GM vehicles, the chassis pitch output is shared with other systems, and a fault in the antilock brake system (ABS) or stability control can trigger P1652 as a secondary code.
  • Intermittent P1652 codes often occur due to water intrusion into connectors under the vehicle, so pay close attention to weatherpack seals and dielectric grease.
  • Do not overlook the possibility of a faulty ignition switch or power mode master causing voltage irregularities that affect the PCM's output drivers.

Can I keep driving with P1652?

You can generally continue driving with P1652, but be aware that stability and traction control systems may be disabled, reducing safety in slippery conditions. Avoid aggressive driving or towing until the fault is repaired, and have the vehicle inspected soon to prevent further electrical issues.

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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