Skip to content
GTECH Calibration
Portal

P1503

Theft Deterrent System Password Incorrect.

  • Chrysler
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
5
AreaVehicle speed, idle control and auxiliary inputs
03
FaultThe specific fault in that area

What it means

On Chrysler vehicles P1503 is listed as Theft Deterrent System Password Incorrect. The engine control unit and the immobiliser or security module exchange a coded security message at key-on, and the engine control unit saw a password or code that did not match what it expected. This usually points to a module that has been replaced or not paired, or to a communication fault between the modules. The exact modules involved and the pairing procedure vary by model and year.

Symptoms

  • Engine cranks but will not start, or starts and stalls after a second or two
  • Security or key warning light on, flashing or staying lit in the instrument cluster
  • No-start that happens intermittently with the same key
  • Fault code returns straight after being cleared
  • Other communication or security-related codes stored in other modules

Possible causes

  • Engine control unit or security module replaced, swapped or not correctly paired to the vehiclelikely
  • Key or transponder not programmed correctly, or faulty transponderpossible
  • Wiring or connector fault on the data bus between the engine control unit and the security modulepossible
  • Low battery voltage or poor earths corrupting the security message at key-onpossible
  • Faulty immobiliser or security module or antenna ring around the ignition barrelpossible
  • Internal fault or corrupted data in the engine control unitrare

How to diagnose

  1. Read all stored and pending codes from every module and note any communication or security codes alongside P1503
  2. Ask whether any module, key or battery has recently been replaced or any work done on the security system
  3. Check the battery state of charge and charging voltage, and check the main power and earth connections
  4. Try each available key and note whether the security light behaves differently with different keys
  5. Inspect the wiring and connectors at the engine control unit, security module and ignition barrel antenna for damage, corrosion or water ingress
  6. Check the data bus for faults and confirm the security module communicates with the diagnostic tester
  7. Check the manufacturer's service information for the model-specific security pairing procedure and any known issues

How to fix

  • Carry out the manufacturer's security pairing or key-code relearn procedure so the modules and keys match
  • Programme or replace the key if the transponder is faulty or not recognised
  • Repair damaged wiring, connectors or earths on the communication circuit
  • Charge or replace a weak battery, then repeat the relearn procedure
  • Replace a faulty security module or antenna ring and pair it to the vehicle
  • Replace or repair the engine control unit only after other causes are ruled out, then pair it to the vehicle

Can I keep driving?

Medium severity

If the engine starts and runs normally the car can be driven, but it may fail to restart, so get it diagnosed soon. If it will not start it cannot be driven and needs the security system checked or repaired.

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

This code for other makes

Nearby codes