Network, generic

U0017 Medium Speed CAN Communication Bus (-) High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0017 means CAN-Low on the medium-speed CAN, the (-) wire, is held too high, as a rule by contact with battery or another supply voltage. On a differential bus of the high-speed type this short is fatal for traffic: the line cannot be pulled down, no dominant bit appears, and onsemi and NXP both class it among the shorts that make transmission impossible. All body and comfort modules on the segment drop out at once, the gateway records missing messages, and functions such as climate control, locking or the radio may stop responding until the short is removed. No manufacturer documents U0017 publicly; the analogy rests on Saab's terminated two-wire mid-speed GMLAN. With ignition on, CAN-Low near battery voltage confirms the fault.

Likely causes

Medium-speed CAN-Low chafed against a supply wire
Moisture or bent pin linking CAN-Low to a supply contact
Accessory wiring connected to the comfort bus by mistake

Symptoms

  • All comfort and infotainment modules out at once
  • Climate, locking or radio not responding

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–700
Time1–5 h

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

Parts involved

can low wiremodule connector

Related codes

U0008U0010U0015U0016

References: onsemi.com, nxp.com, saabwisonline.com.