P1571

Code

CHRYSLER P — Powertrain

TCS PWM Circuit No Frequency

Brand: CHRYSLER

Type: P — Powertrain

Views: UK: 39 EN: 54 RU: 40

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Page language: EN

Causes

Open or shorted wiring in the TCS PWM circuit
Poor or missing ground or battery feed to the TCS/ABS actuator or control module
Connector corrosion, bent pins or poor terminal contact at the module or actuator
Failed TCS/ABS pump motor, solenoid or actuator (no switching produced)
Faulty ABS/TCS control module (driver or input circuit)
Blown fuse or bad relay supplying the circuit

Symptoms

TCS/ESC and/or ABS warning lamp(s) illuminated
Loss of traction control and/or reduced braking system functionality
Pump motor not running when TCS/ABS requests activation
Possible stored related ABS/TCS codes
Diagnostic trouble codes present on a scan tool

What to check

Read freeze frame data and all stored codes with a scan tool; note related ABS/TCS codes
Visually inspect wiring harnesses and connectors for corrosion, damage, or disconnection at pump/actuator and module
Check relevant fuses and relays for the ABS/TCS circuit
Measure battery voltage and ground integrity at the actuator connector
Use a scan tool to command the pump/actuator and observe responses
Probe the PWM circuit with a digital multimeter and/or oscilloscope to look for PWM frequency and duty cycle

Signal parameters

Expected signal: PWM waveform (voltage switching between 0 V and battery voltage)
Typical frequency range (generic): approximately 50–250 Hz (varies by model)
Duty cycle: variable 0–100% depending on commanded output
Voltage amplitude: near 0 V (low) to battery voltage (high) when switching
Note: consult vehicle-specific service manual for exact frequency and voltage specs

Diagnostic algorithm

Connect an appropriate scan tool and record all stored codes and freeze frame data. Note any additional ABS/TCS or pump-related codes.
Visually inspect connector(s) and wiring to the pump/actuator and ABS/TCS module for damage, corrosion, or loose terminals. Repair as needed.
Check fuses and relays that supply the ABS/TCS module and pump. Replace any blown fuses and retest.
With key on and scan tool connected, command the pump/actuator on while monitoring the circuit. Observe whether the pump energizes and whether any signal is present.
Backprobe the PWM output at the module and at the actuator connector. Use an oscilloscope to verify presence/absence of PWM waveform and measure frequency and duty cycle. If no PWM at module output, suspect module or supply/ground issue.
If PWM is present at module but not at actuator connector, inspect wiring for open or short; perform continuity checks between module and actuator pins. Repair wiring as required.
Measure resistance of the pump motor/actuator coil(s). Compare to specification; a shorted or open motor indicates component replacement.
Verify power and ground at the actuator when commanded. Repair supply or ground faults.
If wiring and actuator check good but PWM still absent at module output, consider module fault. Perform any module reprogramming or replacement only after confirming wiring/actuator integrity.
Clear codes and perform a road/test cycle to confirm repair. Monitor for return of P1571 or related codes.

Likely causes

Open circuit between control module and pump/actuator
Failed pump motor or PWM driver inside the ABS/TCS module
Corroded/loose connector at pump or module
Blown fuse or loss of supply voltage to actuator driver
High-resistance ground causing intermittent/no signal

Fault status

⚠️ Status

TCS PWM control circuit not producing expected frequency. The ABS/TCS control module detects no PWM signal where a variable-frequency pulse is expected.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours

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