Multec (X 12 SZ / X 16 SZ) F0: DATA LIST
| No. | TECH 1 Display | Conditions for Checking | Nominal Value | Trouble Codes | Terminal |
|---|---|---|---|---|---|
| 05 | ENGINE SPEED | Engine running at idle speed, operating temperature | 35, 19 | A 2 /B 3 | |
| Vehicles with MT | 820 to 980 rpm | ||||
| Vehicles with AT | 750 to 910 rpm |
The "ENGINE SPEED " is dependent on various input signals and the control unit programming.
If the actual value is not within the given nominal values, the other sensor signals must be checked first.
| Trouble - shooting: | Nominal Value: | Cause of Fault: |
(If nominal value is not attained)
· Check the inductive pulse pick - up signal P 35:
· Ignition OFF
Disconnect the control unit plug
· Measure voltage:
from: control unit plug Ter. A 2
to: ground
| less than 0.1 V | · Short circuit in wiring harness |
from: control unit plug Ter. A 2
| to: battery + |
from: control unit plug Ter. B 3
to: ground
| less than 0.1 V | |
|---|---|
| from: control unit plug Ter. B 3 | |
| to: battery + |
· Using multimeter, measure resistance:
from: wiring harness plug P 35 Ter. 1
to: control unit plug Ter. A 2
| less than 2 W | · Lead interruption |
from: wiring harness plug P 35 Ter. 1
to: control unit plug Ter. A 2
· Using multimeter, measure resistance:
from: wiring harness plug P 35 Ter. 2
to: control unit plug Ter. B 3
| less than 2 W | · Lead interruption |
from: wiring harness plug P 35 Ter. 2
| to: control unit plug Ter. B 3 |
· Using multimeter, measure resistance:
from: wiring harness plug P 35 Ter. 1 and 2
to: ground
| greater than 100 kW | · Short circuit in wiring harness |
from: wiring harness plug P 35 Ter. 1 or 2
| to: ground |
· Using multimeter, measure resistance:
from: wiring harness plug P 35 Ter. 3
to: control unit plug Ter. A 12
| less than 2 W | · Lead interruption in shielding | |
|---|---|---|
| · Further fault possibilities: | · Defective inductive pulse pick - up |
· Burrs on increment disc (58 - toothed segment disc)
· Gap between inductive pulse pick - up and increment disc incorrect.
See service literature.
· Connect control unit wiring harness plug
· Connect pulse pick - up plug P 35.
· Engine running at idle speed, operating temperature
· Select TECH 1 mode "F8", increase and decrease idle speed with the arrow keys.
| Engine speed increases and decreases | · Carry out test step 04. | |
|---|---|---|
| · Idle speed too high or uneven. | · Loose contact in throttle valve potentiometer |
· Throttle shaft out of alignment
· Throttle valve gap too large or too small, (basic setting: alter only in case of emergency, see Service Instructions).
· Exhaust gas recirculation valve mechanically blocked
· Fault in evaporation control system
· Engine takes in dead air.
· Idle speed regulator seat soiled.
· Spark plugs defective
· Mixture too lean or too rich (see test step 10).
· Battery voltage too high / low
· Odometer frequency sensor / instrument defective or circuit interrupted.