| Test | TECH 1 | Notes | Nominal Values | Pin | Possible |
|---|---|---|---|---|---|
| Step | Display | Trouble | |||
| No. | Codes | ||||
| 34 *) | HALL SENSOR | Engine at idle speed | Slow irregular | 8/19 | 93, 94 |
| (operating temperature) | change in display from | ||||
| INACTIVE | |||||
| to | |||||
| ACTIVE | |||||
| and vice versa |
Note:
*) Test step applies only to C 30 SE engine.
The hall sensor on the high voltage distributor helps cylinder recognition. It informs the control unit about which crankshaft revolution cylinder "1" ignites on. This information is required by the control unit for punctual and accurate fuel injection.
If the hall sensor malfunctions, the control unit selects a random time for injection valve actuation.
The effects of a hall sensor malfunction:
· Open loop systems; worse exhaust gas emissions
· Cold start problems
Trouble-shooting: Nominal Value: Cause of Fault:
(If nominal value is not attained)
Check voltage supply · Lead interruption between
· Connect multimeter to Ter. 3 of control unit Ter. 31 (voltage supply)
hall sensor and measure to ground and hall sensor Ter. 3
(adapter cable from KM-609)
· Ignition ON > 10 V · Control unit defective
· Ignition OFF 0 V
Check ground
· Connect multimeter between control unit 0 ohms · Lead interruption between control unit
Ter. 8 and hall sensor Ter. 2 Ter. 8 and hall sensor Ter. 2 (signal lead)
Check hall sensor:
· Push back rubber grommet
on 3-pin plug of hall sensor
and connect plug
Connect measuring tips of
Multimeter MKM-587-A to signal lead (Ter. 2,
middle contact) and ground (Ter. 1)
· Ignition ON
Push vehicle with gear Display must change between · Hall sensor defective
engaged 12V and 0V
AT vehicles:
Turn engine at crankshaft