Description
The electronic throttle control system (etcs) controls the engine idling speed. The etcs operates the throttle actuator to open and close the throttle valve, and adjusts the intake air amount to achieve the target idling speed.
In addition, the ecm retards the ignition timing and the etcs increases the intake air amount to quickly increase the catalyst temperature at cold start to reduce emissions.
Monitor description
The ecm monitors the intake air amount during idling and the ignition timing.
When the engine coolant temperature (ect) is between -10°c and 50 °c (14°f and 122°f), the ecm calculates the idling intake air amount for 10 seconds, beginning 3 seconds after the engine starts.
When the accumulated value is below the threshold, the ecm interprets this as a malfunction in the idle speed control (isc) system at cold start.
The ecm also monitors the ignition timing at cold start, and judges it to be incorrect when it is advanced to the same value for a warm engine for 5 seconds or more of the 10 second monitoring period.
Example:
P050a is detected when all conditions below are met (2 trip detection logic).
The ecm sets the dtc and illuminates the mil 13 seconds after the engine is next started.
Notice:
When the negative battery terminal is disconnected during inspection or repairs, the isc learning values are cleared. The isc learning must be performed by warming up the engine and idling for 5 minutes with the ect at 75°c (167°f) or more because dtcs cannot be detected with the isc learning values cleared.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Inspection procedure
Hint:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
Hint:
If any dtcs other than p050a and p050b are output, troubleshoot those dtcs first.
Hint:
Calculate the total fuel trim values to check the characteristic deviation of the mass air flow meter.
Ok: total of short ft #1 and long ft #1 values is between -20 % and 20 %.
Ok: pcv hose is connected correctly and is not damaged.
Ok: air cleaner filter element is not excessively contaminated with dirt or oil.
Go to step 15
Go to step 15
Go to step 15
Go to step 15
Go to step 15
Ok: no deposits around throttle valve and throttle valve moves smoothly.
Go to step 15
Go to step 15
Notice:
In this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).
Ok: stable fast idling.
Ok: no dtc output.
For vehicles equipped with vehicle stability (vsc) system
Notices when using drum tester
Before beginning testing, disable the vsc. To
disable the vsc, turn the ignition switch off
and connect sst to terminals 12 (ts) and 4
(cg) of the dlc3.
Sst 09843-18040
Notice:
Confirm that the vsc warning light blinks.
Vsc system will be r ...
BMW Drive Recorder
Concept
The system stores brief video recordings of the
surrounding area of the vehicle, e.g., to document
traffic events.
Additionally, the following parameters are stored
for the trip:
Date.
Time.
Vehicle speed.
GPS coordinates.
General information
There are various ways for storing video re ...
Blower resistor
On-vehicle inspection
Inspect blower motor control
Measure the resistance of the blower resistor.
Standard resistance
If the resistance is not as specified, replace the
blower motor control. ...