Open circuit, short or chafed wiring in the TCS PWM signal line between the PCM and the traction control or brake module; Corroded, loose or damaged connector terminals at the PCM or traction control module; Fault in the traction control or ABS module not sending the PWM signal; Blown fuse or poor power or earth supply to the traction control module; Faulty wheel speed sensor or related ABS fault causing the module to stop outputting the signal; Internal fault in the PCM input or output circuit.

P1571

TCS PWM Circuit No Frequency.

Saturn
Powertrain
Manufacturer code
Low severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
5: AreaVehicle speed, idle control and auxiliary inputs
71: FaultThe specific fault in that area

What it means

On a Saturn, P1571 means the engine control module has detected no frequency on the traction control system (TCS) PWM circuit. The PCM expects a pulse-width-modulated signal passing between it and the traction control module, and it has seen that signal missing or dead. The exact circuit layout and wire colours depend on the model and year, so check the wiring information for the specific vehicle.

Symptoms

Traction control warning light on
Traction control not working or cutting in at the wrong time
Engine check light on
ABS warning light on at the same time on some models
Reduced or inconsistent engine torque intervention during wheel slip

Possible causes

Open circuit, short or chafed wiring in the TCS PWM signal line between the PCM and the traction control or brake modulelikely
Corroded, loose or damaged connector terminals at the PCM or traction control modulelikely
Fault in the traction control or ABS module not sending the PWM signalpossible
Blown fuse or poor power or earth supply to the traction control modulepossible
Faulty wheel speed sensor or related ABS fault causing the module to stop outputting the signalpossible
Internal fault in the PCM input or output circuitrare

How to diagnose

Read all stored and pending codes and note the freeze frame data, paying attention to any ABS or traction control codes stored alongside P1571.
Check the traction control and ABS fuses and the module power and earth connections.
Visually inspect the wiring and connectors between the PCM and the traction control or brake module for chafing, water ingress, corrosion and pushed-back pins.
Check the wheel speed sensors and their wiring, and look for any related ABS codes.
Using the wiring diagram for the specific model, test the PWM signal wire for continuity, short to earth and short to voltage.
With a suitable scope or meter, check whether the PWM signal is present at the module output and at the PCM input.
Check whether the traction control module is communicating and works correctly, and only then suspect the module or PCM.
Clear the code and road test to see whether it returns.

How to fix

Repair or replace damaged wiring in the PWM signal circuit.
Clean or replace corroded or damaged connectors and terminals.
Replace blown fuses after finding out why they failed, and restore good power and earth supplies.
Repair any wheel speed sensor or ABS fault that is stopping the signal.
Replace or repair the traction control or ABS module if it is confirmed faulty, and programme it as required.
Replace the PCM only if testing proves an internal fault.

Can I keep driving?

Low severity

The car is usually safe to drive, but traction control may not work, so take extra care on wet or slippery roads. If the ABS light is also on, have it checked soon, as braking systems may be affected.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.