Multec (X 12 SZ / X 16 SZ) F0: DATA LIST
| No. | TECH 1 Display | Conditions for Checking | Nominal Value | Trouble Codes | Terminal |
|---|---|---|---|---|---|
| 10 | O2 SENSOR | Ignition ON | |||
| Engine cold | 350 to 550 mV | 13, 44, 45 | B 11 / | ||
| B 10 | |||||
| Engine running at idle speed, operating temperature | 50 to 950 mV | ||||
| alternating | |||||
| Trouble - shooting: | Nominal Value: | Cause of Fault: |
(If nominal value is not attained)
Part 1
· Disconnect wiring harness plug from oxygen sensor.
· Measure voltage:
from: wiring harness plug P 33, wiring harness side
to: battery -
| · Ignition ON. | 450 mV± 20 mV | · Lead interruption |
from: wiring harness plug P 33
to: control unit K 57 Ter. B 11
· Short circuit in wiring harness
from: control unit K 57 Ter. B 11
to: ground (display less than 100 mV)
· Lead interruption
from: control unit K 57 Ter. B 10
to: ground (display of 800 to 1000 mV)
· Short circuit in wiring harness
from: control unit K 57 Ter. B 11
to: battery + (display greater than 1000 mV)
· Control unit defective.
· Measure voltage:
from: wiring harness plug P 33, wiring
harness side
to: grounding point on valve cover (old fastening point for fuel pump)
| 450 mV ± 20 mV | · Transfer resistance at grounding point too high / large (clean battery lug, stud and fastening nut) |
· Control unit defective.
· Engine in TECH 1 mode "F6". submode "F0".
Using arrow keys, set at 1300 rpm.
· Measure voltage:
from: oxygen sensor plug P 33
to: ground (oxygen sensor plug disconnected)
| 50 to 950 mV | · Oxygen sensor defective | |
|---|---|---|
| · Accelerate briefly. | greater than 700 mV | · Mixture constantly too lean / rich. (see overleaf) |
· Oxygen sensor defective
Part 2
Mixture constantly too rich
(Oxygen sensor voltage greater than 600 mV)
| · Check fuel pump pressure | ||
|---|---|---|
| Feed pressure: | approx. 0.75 bar (idle) | |
| Return pressure: | approx. 0.3 bar | · Return lead blocked / kinked |
· Leaky injector (drips)
· Controlled canister purge system defective (see test step 22)
· Temperature sensor P 30 defective (see test step 02)
· Intake manifold pressure sensor P 23 defective (see test step 03)
· Intake manifold pressure sensor hose leaky / jammed
· Throttle valve potentiometer P 34 defective (see test step 04)
· Fuel pressure regulator defective
· Incorrect injector
| If all nominal values are attained: | · Check timing of valves and examine for leaks. |
· Internal exhaust gas recirculation rate too large.
| · Control unit defective |
Part 3
Mixture constantly too lean
| (Oxygen sensor voltage less than 300 mV) | ||
|---|---|---|
| · Check fuel pump pressure | ||
| Feed pressure: | approx. 0.75 bar (idle) | |
| Return pressure: | approx. 0.3 bar | · Feed line blocked / kinked |
· Injector blocked or defective
· Connection line from air cleaner to throttle body leaky
· Controlled canister purge system defective (see test step 22)
· Intake manifold pressure sensor P 23 defective (see test step 03)
· Intake manifold pressure sensor hose defective
· Coolant temperature sensor P 30 defective (see test step 02)
· Throttle valve potentiometer P 34 defective (see test step 04)
· Fuel pressure regulator defective
· Intake system leaky
· Exhaust system leaky
· Poor fuel quality
· Incorrect injector
· Control unit defective