Component Tests and General Diagnostics
Notes on BMW DIAGNOSE-SYSTEM
Defect Code Memory
The component functions and signals listed below are processed or controlled by the DML control unit, but not stored as a detect code in the case of defect:
- LL-signal (sends the "idle" information to the DME)
- VL-signal (sends the "full load" information to the DME)
- A/C switch
- A/C corn presser clutch (lock sensor)
- Range selector switch ("P" or "N" posit on in automatic transmission)
- Clutch switch (manual transmission)
- Brake light switch
- External safety path
The external safety path cannot be read out in the status lists of the BMW DIAGNOSTIC SYSTEM.
Defect Code Priority
The EML control unit stores a maximum of 5 defect codes. When the defect code memory is full, a new detect code with higher priority displaces a lower priority defect code already stored.
Status Monitoring
Since all inputs and outputs and their plausibilities are not covered by the defect code memory of the EML control unit, the status monitoring functions must be used to facilitate troubleshooting.
The nominal values and actual values indicated in the status lists need not necessarily agree exactly. The EML control unit stores a defect code if the deviation between the nominal value and the actual value is outside the permissible range.
For the permissible ranges, refer to the functional description or the troubleshooting description in the BMW DIAGNOSTIC SYSTEM. If the permissible range has been exceeded and the EML control unit has detected this as a defect, the component and its line connection can be checked without complex measurements with the aid of the actual value display.
Abbreviations
ABS Anti-lock brake system
ASC Automatic stability control
DME Digital engine electronics
EGS Electronic transmission control
EML Electronic throttle control
MSR Engine drag torque control
A Output
E Input
DK EML throttle
DKV Set throttle value
DKR Throttle reduction
DKE Throttle increase
HG Manual transmission
ME Engine intervention
PWG Pedal position sensor
Poti Potentiometer
TD Engine speed signal (once per ignition)
TR Engine speed signal (three times per crankshaft revolution)
TMOT Engine temperature sensor
ti Injection signal
LL Idle signal
VL Full load signal
WK Torque converter clutch
ZAB Ignition fade-out
Pin Assignments
Pin Assignments at the EML 12-cyl. Control Unit Connector X6004
Adapters:
Troubleshooting
NOTES
- Relevant safety codes and accident prevention regulations must be observed when carrying out all tests and work on the engine electronic system. Do not touch an EML throttle valve when it is in operation.
Important! Wherever possible, the battery and the instrument cluster should not be disconnected otherwise all detect codes and teach-in values stored in the EML control unit will be deleted.
Disconnect control unit from the wire harness only when the ignition is switched off
Attention! The stage outputs of the EML control unit for the throttle (DK) actuators are not short-circuit-proof. In the same way, the 5 V component supply voltage coming from the EML control unit is not absolutely short-circuit-proof.
Organisation of the Defect Code Pages on the Display Screen
- Defect location: The defect can be in the vicinity of the component, the associated wires or in the control unit. The number before the defect cede indicates the priority of the defect code.
- Type of defect: Range transgression or illogical (wrong sequence) functions are indicated.
- Detected at: Additional defect information on the operating statuses during defect detection (compare values with substitute values). This information can provide an indication relating to plausibility (correct sequence), shorts, breaks and range transgressions.
EML Warning Lamp
After switching on the ignition, EML control unit checks its vital components (safety check) and causes the EML warning lamp to light for approx. 2 seconds.
The EML reduces the output if the EML warning lamp cannot be set due to a defect in the lamps or associated wires. The warning lamp continues to light if one of the defects B to 22 occurs after the safety check.
Defect Code Table
*D* Defect code memory - stored detect codes
One or several defect codes stored troubleshooting in accordance with BMW
DIAGNOSTIC SYSTEM.
