U0194

U0194 00

U0194 00: SDAR or EHU Missing on BUS

Fault symptoms

Fault in the ignition switch logic of the radio.
It has not been possible to contact SDAR or EHU.
No satellite radio sound.

Type of diagnosis

Continuous.

Enable criteria

Radio/CD switched on or ignition on.

Fault criteria

No bus communication with SID.

Diagnostic help

If there is a diagnostic trouble code stored and it has been read by the diagnostic tool then this indicates that there is an intermittent bus lead fault.

If U0140 and U0194 are stored at the same time then this indicates that it is either the EHU bus lead or a short circuit on the bus that has been the problem. This applies to cars with SDAR.

Checking the wiring harness

Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short circuits. Check switches, connectors and crimp connections for oxidation, withdrawn pins and pin clamping force.

Fault Diagnosis Procedure