P1608

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE. Tachometer not working (MIU). Temperature gauge not working (MIU). Fuel consumption calculation not working (SID).

P1608

Fault symptoms

•	CHECK ENGINE.

•	Tachometer not working (MIU).

•	Temperature gauge not working (MIU).

•	Fuel consumption calculation not working (SID).

On-Board Diagnostics

Type of diagnosis:

-	Continuous.

Enable criteria:

-	Engine running.

Fault criteria:

-	BUS communication between ECM and MIU is down for more than 10s.

Dependents:

-

None.

System reaction to a fault:

-

None.

OK report:

-	BUS communication between ECM and MIU is available for more than 1 s.

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

-

Type III.

Diagnostic help

The diagnosis concerns an electrical fault in bus communication between ECM and MIU.

When diagnostics communication can be maintained with ECM, it indicates an intermittent fault on the wiring harness between ECM and MIU.

Functions in the diagnostic tool related to the fault:

-	Read value: Engine RPM (ECM), Engine RPM (MIU)

See also description of read value under "Read Values" menu for more information.

Checking the wiring

Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short circuits. Observe the multimeter, diagnostic tool or test lamp during the check.