01 Understanding & Fixing Catalytic Converter Problems • 02 How a Nitro Car Engine Works • 03 Eco-Friendly and Powerful: The Best Fuel-Efficient SUVs for… • 04 How A Simple Mistake At The Gas Pump Could Destroy Your Eng… • 05 How to Become a Pilot: A Guide for Aspiring Aviators • 06 Knock Sensor Warning Signs: Prevent Engine Damage Before It… • 07 P0012 A Camshaft Position - Timing Over Retarded (Bank 1) • 08 Why the Toyota 1NZ Engine Is So Popular (And Its Weaknesses) • 09 The Hidden Truth About Why Rear Brake Pads Wear Out So Quic… • 10 P0104 - Mass Air Flow Circuit Intermittent •

DTC codes / Chrysler codes / P1597

P1597 · ChryslerSpeed Control Switch Always Low

P1597 on a Chrysler vehicle means the speed control switch circuit is reporting a continuous low-voltage condition to the powertrain control module (PCM). The PCM expects the switch to produce different voltage levels for each button press, and it has detected the circuit stuck at or near ground for longer than expected.

SystemPowertrain
Code typeChrysler specific
SeverityLow
Fix difficultyIntermediate
AreaVehicle speed, idle control and auxiliary inputs

Symptoms you may notice

  • Cruise control does not engage or cancels immediately after being set
  • Horn may not work if the speed control switches share the same clock spring circuit
  • Steering wheel audio controls may become erratic or stop working
  • Often no symptoms besides the warning light, with cruise control appearing to function normally
  • Speed control buttons may feel unresponsive or require excessive pressure
  • Intermittent cruise control operation that worsens when turning the steering wheel

Common causes, most likely first

  1. Faulty speed control switch assembly on the steering wheel with internal short to ground
  2. Damaged or pinched wiring in the steering column or clock spring (spiral cable)
  3. Corroded or loose connector at the speed control switch or PCM
  4. Failed clock spring causing a short between the switch signal and ground
  5. Water intrusion into the steering column or switch housing
  6. PCM internal fault misreading the switch voltage

How to diagnose and fix it

  1. Scan all modules for related codes and record freeze-frame data to confirm the low-voltage condition
  2. Inspect the speed control switch connector and wiring for corrosion, chafing, or pinched wires
  3. Test the speed control switch resistance with a multimeter and compare to Chrysler specifications
  4. Check the clock spring continuity and resistance while turning the steering wheel through its range
  5. Verify the signal voltage at the PCM connector while pressing each speed control button
  6. Replace the faulty speed control switch or clock spring as indicated by test results
  7. Clear codes and perform a road test to confirm cruise control operates correctly and the code does not return

Why the clock spring is often the real culprit

  • A shorted clock spring frequently sets P1597 because the spiral cable carries the speed control signal and can wear through from repeated steering wheel rotation.
  • Technicians sometimes replace the speed control switch only to find the code returns because the clock spring was the actual source of the short to ground.
  • The speed control switch circuit often shares a ground path with the horn and audio controls, so a horn that does not work can point to the same fault.
  • P1597 can be set by a momentary short during steering column work, so check for recent repairs before condemning parts.
  • On some Chrysler models, a weak or failing battery can cause erratic switch voltages that mimic a low circuit, so always verify battery condition first.

Can I keep driving with P1597?

The vehicle remains safe to drive because the fault only affects cruise control, but avoid using cruise control until repaired since it may not engage or could cancel unexpectedly. Do not attempt to repair the clock spring or steering wheel wiring without proper diagnostic testing, as incorrect repair can affect airbag operation.

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 Chrysler vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage