Network, generic

U0168 Lost Communication With Vehicle Security Control Module

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0168 points to the vehicle security control module, which handles anti-theft and key authorisation and in many layouts also hosts the immobilizer handshake. Chrysler shows the link: its 2011 field report names U0168 for the SKREEM/WCM, and bulletin 18-023-13 (Grand Voyager 2.8 L diesel 2012-2013) treats it as a sign of a failed ignition handshake that new PCM software fixes. Jeep TSB 08-088-25 (Grand Cherokee 4xe 2024) lists it with MIL and a no-start. Mercedes stores U0168 in the 48 V starter-alternator of the 2021 S 580 for the electronic ignition lock; the MIL clears after three drive cycles. GM's Saab list calls it the keyless entry module. U0167 is the immobilizer module, U0427 invalid security data.

Likely causes

Engine or security module software mishandles the key handshake (Chrysler, Jeep, Mercedes updates)
Security module without power or ground
Bus line or connector to the security module faulty
Security or keyless entry module faulty

Symptoms

  • No start or delayed start
  • Check engine light on (Jeep 4xe, Mercedes S 580)
  • Keyless entry, alarm or key detection not working

Repair estimate

DifficultyHardWorkshop job
Parts and labour€60–1,200
Time0.3–4 h

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

Parts involved

vehicle security modulecan bus wiring

Related codes

U0167U0427P0513P0633

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.