Mechanics

BMW 323 FUSE PROBLEM

2000 BMW 323 • 127,000 miles

Its a 323i It failed the ODBII test. No check engine light while driving, no DTC's. I assume that the on-board computer is malfunctioning. The OBMonitor has a 20amps fuse, which should be only 5amps. Same fuse has also (some kind of white trash repair) a wire connected to the fuse. I don't know where it goes, I am not an electrician. I drove 3 drive cycles, drove 50 miles go to the test and it is still not ready, catalyst, evap system and 02 sensor. 02 sensor have 30000 miles and catalytic converter has no holes. I don't know any about the evap system. I know that the lower control arm bushings has to be replace, but never received error codes; had the gas cap loose, no error codes. Even BMW suggested, just to perform drive cycles. I am driving the car forever and 2 years ago it passed. Appreciate a lot if you got any idea.
Thank you so very much! Regina
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Regina49
October 16, 2012.




A wire connected to the fuse indicates it is being used to add something on or somewhere a circuit is missing power and thsi line is used for supplying the power, hence the higher apmerage used.

Any disruption of this fuse would result in the monitors not functioning correctly and woule be resetting itself. Move the wire to another location if it needs to be used.

For the drive cycles, avoid abrupt accelerations. Drive gently and try running on the highway for 20 minutes at a steady speed. Move to city driving conditons for at least 10 minutes and back on the highway again for another round and retest. Ensure the fuse is secure and does not have the possibility of interruptions in power supply.

KHLow2008
Oct 16, 2012.
Readiness Monitors and Drive Cycles

"Readiness Monitors" are indicators that demonstrate whether or not emission system components are being monitored (checked) by the OBDII system. If a monitor is set to "Ready" the monitor is checking its assigned component and, if no DTC's are present, the vehicle should pass an emissions test.

NOTE: If the appropriate number of Readiness Monitors (codes) are not flagged as "Ready", in most cases, the vehicle can not pass an emissions test. See State and Federal Laws.

The status of all readiness monitors is reset to "Not Ready" : Each time DTC's are cleared
The battery is disconnected
The ECM is disconnected

The status of all readiness monitors is reset to "Ready" : After DTC's are cleared and the appropriate drive cycle(s) is successfully completed

EPA Federal Test Procedure

Manufactures are required to validate monitors during the first 23 minutes (1372 seconds) of the Federal Test Procedure Drive Cycle.

EPA Urban Dynamometer Driving Schedule

Completing the Drive Cycle successfully one (1) time should reset most drive cycle monitors to a "Ready" status. However, there are "two trip" monitors, which require that the drive cycle be successfully completed two (2) times, to achieve a "Ready" status. Furthermore, systems which use averaging, may require the drive cycle to be completed more than 2 times.

Verify the status of the readiness monitors with the appropriate function of your scan tool.

NOTE: Certain vehicles have known OBDII Readiness issues. Please be sure to review TSB's for special circumstances and or exceptions to readiness monitor resetting procedures.

Before Beginning the Drive Cycle
Check the status of the Readiness Monitors, check for DTC's, correct faults, clear DTC's before beginning the Drive Cycle.

Begin Drive Cycle
The vehicle should be driven approximately 7.5 miles within a period of approx. 23 minutes (1372 seconds) from a cold start. However, due to manufacture variations, it is necessary to perform only as much of the Drive Cycle as is necessary to reset the required monitors to a "Ready" status. Operate the throttle smoothly to obtain best results. Do not turn the ignition off during the drive cycle.

CAUTION: Obey all traffic laws and drive in a safe manner!

NOTE: Extreme driving conditioning such as very high/low temperatures, rough roads and high altitudes may prevent some monitors from attaining a "Ready" status.

Step 1 (Engine Cold) Start engine, idle 20 seconds. Accelerate gradually and drive at 20-25 mph for 1 minute, varying speed.
Step 2 Accelerate gradually to 32 mph within 35 seconds. Decelerate to 0 mph in 10 seconds. Idle for 40 seconds.
Step 3 Accelerate at part throttle to 25 mph in 10 seconds. Cruise at 17-25 mph for 15 seconds. Accelerate gradually to 57 mph in 45 seconds. Cruise at 50-56 mph for 1 minute. Decelerate gradually to 0 mph in 40 seconds. Idle for 15 seconds.
Step 4 Accelerate at part throttle to 36 mph and maintain for 10 seconds. Decelerate to 0 mph in 15 seconds. Idle for 5 seconds.
Step 5 Accelerate to 30 mph and back to 0 mph within 30 seconds. Idle for 20 seconds.
Step 6 Accelerate to 36 mph in 20 seconds. Drive at 35 mph for 20 seconds. Decelerate to 0 mph in 15 seconds. Idle 5 seconds.
Step 7 Accelerate gradually to 26 mph and decelerate to 0 within 40 seconds. Idle 15 seconds.
Step 8 Accelerate to 27 mph in 40 seconds. Decelerate to 0 mph in 10 seconds. Idle 25 seconds.
Step 9 Accelerate to 26 mph in 15 seconds, maintain speed for 10 seconds, decelerate to 0 mph in 10 seconds. Idle 15 seconds.
Step 10 Accelerate to 23 mph in 20 seconds, decelerate to 0.5 mph in 10 seconds (no complete stop). Accelerate to 28 mph and back to 0 mph (momentary stop 1 second) within 35 seconds.
Step 11 Accelerate gradually to 34 mph in 45 seconds. Vary speed between 34 and 19 mph for 2 minutes. Decelerate from 25 to 0 mph in 25 seconds. Idle for 5 seconds.
Step 12 Accelerate to 29 mph in 15 seconds, decelerate gradually to 0 mph in 45 seconds. Idle for 30 seconds.
Step 13 Accelerate gradually to 28 mph and back to 0 mph (momentary stop 1 second) within 50 seconds. Accelerate gradually to 27 mph and back to 0 mph within 55 seconds. Idle for 15 seconds.
Step 14 Accelerate to 24 mph and back to 0 mph within 18 seconds. Idle for 10 seconds. Accelerate gradually to 22 mph and back to 0 mph within 50 seconds. Idle for 8 seconds.
Step 15 Accelerate gradually to 30 mph within 50 seconds. Decelerate to 0 mph in 10 seconds. Idle for 25 seconds.
Step 16 Accelerate to 23 mph and back to 0 mph within 30 seconds. Idle for 10 seconds.
Step 17 Repeat steps 1 - 16 once again. Recheck the status of the "Readiness Monitors".

NOTE: Remember, clearing DTC's or interrupting power to the ECM after the readiness monitors have been reset to "Ready" will require that the Drive Cycle be repeated.

Completing the Drive Cycle successfully one (1) time should reset most drive cycle monitors to a "Ready" status. However, there are "two trip" monitors, which require that the drive cycle be successfully completed two (2) times, to achieve a "Ready" status. Furthermore, systems which use averaging, may require the drive cycle to be completed more than 2 times. It is necessary to perform only as much of the Drive Cycle as is necessary to reset the required monitors to a "Ready" status.

End Drive Cycle

Wrenchtech
Oct 16, 2012.
Make sure the under hood 20 pin diagnostic plug is screwed all the way in, if loose, it will not run the monitors to completion.
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Dr. Hagerty
Oct 18, 2012.
Was the outcome satisfactory?

Dr. Hagerty
Dec 7, 2012.

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