P1596
Speed Control Switch Always High.
- Plymouth
- Powertrain
- Manufacturer code
- Low severity
How this code is built
- P
- SystemPowertrain
- 1
- Defined byThe manufacturer
- 5
- AreaVehicle speed, idle control and auxiliary inputs
- 96
- FaultThe specific fault in that area
What it means
On Plymouth (Chrysler-built) vehicles, P1596 means the speed control (cruise control) switch circuit has been seen at a constantly high voltage. The powertrain control module monitors the switch input and sets the code when the signal stays high outside the range expected for the switch being released or pressed. Cruise control is normally unavailable while the fault is present.
Symptoms
- Cruise control will not engage or set
- Cruise control cancels or behaves erratically
- Cruise control light or switch indicator not working as expected
- Check engine light on
- Cruise buttons seem stuck or unresponsive
Possible causes
- Faulty or worn speed control switch (stuck contacts or internal fault)likely
- Clock spring or steering wheel switch wiring fault (where fitted)likely
- Short to voltage or damaged wiring in the switch signal circuitpossible
- Open circuit in the switch ground or return circuit, causing a high readingpossible
- Corroded or loose connector at the switch or powertrain control modulepossible
- Faulty powertrain control module input circuitrare
How to diagnose
- Read the stored and pending codes and freeze frame data, noting any other cruise, brake switch or vehicle speed codes
- Check the cruise control switch operation and whether any button feels stuck or sticky
- Inspect the switch connector, steering column wiring and clock spring area for damage, moisture or corrosion
- With the switch released, view the live switch input in the scan data and compare it with the manufacturer's expected values, which vary by model
- Press each switch function and watch the signal change; a reading that never leaves high points to the switch or its ground
- Measure the reference voltage, signal and ground circuits at the switch connector against the wiring diagram for that model
- Check the signal wire for a short to voltage and the ground wire for an open circuit or high resistance
- Only after wiring and switch are proven good, test the powertrain control module input and check for any applicable software updates
How to fix
- Replace the faulty speed control switch or steering wheel switch assembly
- Replace the clock spring if it is found to be faulty (model dependent)
- Repair or replace damaged wiring, including shorts to voltage or open grounds
- Clean, repair or replace corroded or loose connector terminals
- Replace or reprogram the powertrain control module only if a confirmed fault is found with its input circuit
Can I keep driving?
Low severity
The car is safe to drive, but cruise control will probably not work. Book it in for repair at your convenience.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.