P1656

Read the instructions below then start the fault diagnostic procedure.

Symptom: A/C not working. Compressor may run continuously.

P1656

Fault symptoms

•	A/C not working.

•	Compressor may run continuously.

On-Board Diagnostics

Type of diagnosis:

-	Continuous. But interrupted when fault criteria fulfilled and will not restart until next driving cycle.

Enable criteria:

-	Ignition in ON position. A/C request has previously arrived on bus on some occasion (cars with A/C). Output not active.

Fault criteria:

-	Output voltage below 2V for more than 1 s.

Dependents:

-

None.

System reaction to a fault:

-	Air mass control A/C compensation blocked.

OK report:

-	Enable criteria fulfilled. A/C (Bus from DICE) is ON and fault criteria not fulfilled within 1.5 s.

Fault handling: (See section Fault handling III, other emission-related components and functions for more information.)

-	Type III. CHECK ENGINE does not go on.

Diagnostic help

Fault diagnosis concerns electrical fault in connecting leads or in the relay.

Functions in the diagnostic tool related to the fault:

•	Activation of output for A/C relay.

See also description on activating under "Activate" menu for more information.

Check the wiring

Jiggle the leads and in-line connectors at various points and in different directions to detect any intermittent breaks or short circuits in the wiring. Observe the multimeter, test lamp or diagnostic tool while doing this.