Powertrain, generic · Computer and auxiliary outputs

P0602 Control Module Programming Error

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0602 reports that the module is not, or not completely, programmed for this vehicle. GM checks at power-up and then every second whether a service replacement module still carries no calibration, and sets the code in the first trip; in brake modules a missing calibration set or a sensor ID that does not match also counts. Ford uses P0602 when the checksum of the vehicle identification block (tyre size, axle ratio, VIN) is wrong. Typical triggers are a new module that was never programmed, a reflash interrupted by a voltage dip or lost connection, or wrong software. Depending on the maker the engine may not start, run with reduced power or only show the lamp; GM Europe engines show a service lamp instead of the check engine light. The fix is almost always reprogramming with a stable power supply; replace the module only if the code returns.

Likely causes

Module replaced and not (completely) programmed
Programming interrupted by a voltage dip or lost connection
Wrong or incompatible software, calibration or configuration block
Internal memory defect in the module

Symptoms

  • Check engine light or service lamp
  • Engine may not start or runs in limp mode
  • Reduced engine power
  • Appears right after a module replacement or software update

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–1,200
Time0.5–2 h

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

Parts involved

engine control modulecontrol module power supplycontrol module ground

Related codes

P0601P0605P0610P0630P0603

References: law.cornell.edu, gsi.ext.gm.com, newtonnet.co.uk, saabwisonline.com.