B1785A

Read the instructions below then start the fault diagnostic procedure.

Symptom: The message “SERVICE ANTI-THEFT ALARM” is shown on SID.

B1785A

Fault symptoms

The message “SERVICE ANTI-THEFT ALARM” is shown on SID.

Enable criteria

Battery voltage must be 11-14 V.

Fault criteria

Low voltage in the siren internal battery.

Diagnostic help

The diagnostic trouble code is generated if a fault is found during two test cycles in succession. A test cycle lasts one second, i.e. it takes two seconds from when the fault occurs until a diagnostic trouble code is generated. If the fault disappears, the trouble code is cleared from the control module memory after the ignition has been turned on 20 times.

Check wiring harness.

Jiggle the wiring harness at several points and in different directions to reveal intermittent breaks and short-circuits in the leads. Observe the multimeter, test lamp or diagnostic instrument during the test.