What are common causes for U0072?

Persistent short on CAN-L wire (high) · Gateway module routing CAN messages incorrectly (low) · CAN terminating resistor (120 Ω) drifted out of spec (low)

What symptoms does U0072 show?

Multiple warning lights may illuminate · Affected modules may go into limp mode or shut down · Specific functions inoperative depending on module · Diagnostic tools may show communication faults

Network generic / SAE

U0072

Vehicle Communication Bus A (-) Bus Off

The CAN controller for bus A has gone bus-off on the minus side. Common after a CAN-L short or a faulty transceiver pulling the bus low.

SystemNetwork

Typegeneric / SAE

GroupU0

Range / number– / 72

Possible causes

Persistent short on CAN-L wire high
Gateway module routing CAN messages incorrectly low
CAN terminating resistor (120 Ω) drifted out of spec low

Symptoms

Multiple warning lights may illuminate
Affected modules may go into limp mode or shut down
Specific functions inoperative depending on module
Diagnostic tools may show communication faults

Inspection / repair

Difficulty: hard
DIY: shop recommended
Estimated cost: 80–800 €
Estimated time: 1–6 h
Component: can transceiver
Component: can low wire
MIL / check engine light
limp mode possible

Sources

Wikipedia · CAN bus

References

sae:J2012 iso:11898