Powertrain, generic · Computer and auxiliary outputs

P0633 Immobilizer Key Not Programmed ECM/PCM

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

The immobiliser couples the engine module to the immobiliser control module (GM body module, Chrysler SKIM/WCM) through a secret key and a challenge-response exchange – 'key' here means these security data, not the ignition key. P0633 means the engine module has not learned this secret key yet. At GM and Saab the code is set automatically whenever the engine module enters learn mode, for example as a new part, and clears after a successful learn and engine start; it is only a real fault if learn mode does not end, often because the engine fails to start for another reason. Chrysler calls it 'SKIM secret key not stored in PCM' and fixed false settings on the 2012–13 Grand Voyager 2.8 diesel by software. The engine does not start or dies after one or two seconds; the security lamp, not the check engine light, comes on.

Likely causes

Engine module replaced, immobiliser not learned
Learn procedure aborted or learn mode not exited (no start for another reason)
Communication fault to the immobiliser module
Engine module software fault (false setting)

Symptoms

  • Engine does not start or dies immediately
  • Security or immobiliser lamp on or flashing
  • Code present after engine module replacement until learned
  • Sometimes immobiliser communication codes

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–400
Time0.5–1.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

engine control moduleimmobilizer module

Related codes

P0513P0630P0602P0610

References: law.cornell.edu, saabwisonline.com, saabwisonline.com, static.nhtsa.gov.