B3940 05

B3940 05

Block Heater Relay Circuit, Open/Short to B+







Fault symptom
- No heating in car when parking heater activated.

On-board diagnosis

Type of diagnosis:
- Continuous

Enable criteria:
- Ignition ON.
- Relay not activated.

Fault criteria:
- When the current on the output is 0 A.

Checking the wiring harness
- Move the wiring harness at several spots and in several directions to reveal intermittent breaks and short-circuits. Check switches, connectors and crimp connections for oxidation, retracted pins and pin clamping force.

Diagnostic help

Diagnosis regards:
- Electrical fault in connecting leads or component.

Functions in the diagnostic tool related to the fault:

Activation:
- Block Heater Relay
(See also description of readings/activations in diagnostic tool)