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Drive Cycle Monitor

41K views 20 replies 9 participants last post by  chlenz62 
#1 · (Edited)
Im Trying to get my drive cycle monitors to pass.
I Had code for a Pre Cat o2 sensor fixed that then a code for the Secondary air got that working now ive driving over 1400 Miles and it still wont set!
I ve tried clearing the codes once and disconecting the battery.

I Have done the proper BMW Drive Cycle a few times but the only monitor that competes is the o2 heater.
 
#3 ·
There is no codes set. Its just the self test for the emmisions wont complete or run. And ive driving it per the BMW Drive cyle thing Idle on cold for 2:15min - 25mph for 3:15min - 55mph for 15min - Idle in gear for 5min but the only emmision test that competes or runs is the o2heater
 
#5 ·
My GF's jetta is doing the same bs right now. It is really frustrating. For some reason, 2 monitors are are not ready even though the correct drive cycle has been done. I was reading that specific obd 2 scanners can create this condition when you use them to clear the codes. I was told that I may have to take it to a shop with a factory diagnostic tester in order to reset the monitors correctly.
 
#6 · (Edited)
Sigh...I'm fighting the readiness monitors on my M3 right now after the dealer flashed the ECU with an emissions recall (which, ironically, was so that smog shops can read the OBD2 readiness monitors). Mind you, I've collected a small library of drive cycle methods now, a few from BMW and the general OBD2 one.

Here's a TSB on the issue:
http://www.bimmerfest.com/forums/showthread.php?t=219337

Note that there are quite a few conditions that have to be met for each test to complete, including intake air temperature and coolant temperature. If it's too cold out, some tests may not even run.
The secondary air injection, O2 sensor heating, and O2 sensor functional tests should complete pretty easily. Catalyst and EVAP are the tough ones, it seems.
 
#11 ·
As an aside...I'd recently heard that a couple of car manufacturers...I forget which ones...actually had a method for doing the drive cycle with software only. Didn't get the details, but evidently, you plug in the car and it does what it needs to do to set monitors while just running in a garage. Seems like it'd be illegal in my state, but I don't think it is.

I was surprised mostly, because obviously the load when driving, fuel used, etc, is very different when driving than just running. Maybe someday bmw will have something similar.

Also, another aside, some of the monitors, probably sap or evap, might need to be 'ready' more than once to pass. Anyone know about either of these things?
 
#12 · (Edited by Moderator)
Also, another aside, some of the monitors, probably sap or evap, might need to be 'ready' more than once to pass. Anyone know about either of these things?
the SAP should be tested and set ready after a cold start (engine off more than 5 hours) and idling for 2 minutes and 15 seconds.

Page 7 -
http://www.beisansystems.com/misc/SEIMENS_MS_420_ENGINE_CONTROL_SYSTEM.pdf

Conditions for Secondary Air Pump Activation:
*NOTE: Below -10°C the air injection pump is activated only as a preventive measure to
blow out any accumulated water vapor that could freeze in the system.
REQUIREMENTS STATUS/CONDITION
M52 STATUS/CONDITION

Oxygen sensor Open Loop
Oxygen sensor heating Active
Engine coolant temperature -10 to 40ºC*
Engine speed Predefined Range
Fault Codes No Secondary Air Faults "currently present"



For the evap the MS42 runs the test during the first Idle stage same as the SAP. The MS43 runs the DM-TL (evap) test after the engine is turned off.
But not every time!!

http://www.bmwmotorsports.org/BMW_docs/m54x5.pdf
page 20
LEAK DIAGNOSIS TEST PRECONDITIONS
The ECM only initiates a leak diagnosis test every second time the criteria are met. The criteria is as follows:
  1. Engine OFF with ignition switched OFF.
  2. Engine Control Module still in active state or what is known as "follow up mode" (Main Relay energized, control module and DME components online for extended period after key off).
  3. Prior to Engine/Ignition switch OFF condition, vehicle must have been driven for a minimum of 20 minutes.
  4. Prior to minimum 20 minute drive, the vehicle must have been OFF for a minimum of 5 hours.
  5. Fuel Tank Capacity must be between 15 and 85% (safe approximation between 1/4 -3/4 of a tank).
  6. Ambient Air Temperature between -7C & 35C (20F & 95F )
  7. Altitude < 2500m (8,202 feet).
  8. Battery Voltage between 11.5 and 14.5 Volts
 
#15 ·
For the evap test to complete you have to have between about 1/4 and 3/4 of a tank and may have to complete two drive cycles. It is only run every other time the drive cycle is met on the BMW MS43 ECM.

• Engine OFF with ignition switched OFF.
• Engine Control Module still in active state or what is known as "follow up mode" (Main Relay energized, control module and DME components online for extended period after key off).
Prior to Engine/Ignition switch OFF condition, vehicle must have been driven for a minimum of 20 minutes.
Prior to minimum 20 minute drive, the vehicle must have been OFF for a minimum of 5 hours.
Fuel Tank Capacity must be between 15 and 85% (safe approximation between 1/4 -3/4 of a tank).
• Ambient Air Temperature between -7C & 35C (20F & 95F )
• Altitude < 2500m (8,202 feet).
• Battery Voltage between 11.5 and 14.5 Volts
 
#16 ·
I'm focusing on the Secondary Air monitor as I believe it may be the easier monitor to solve. I've read the "spaghetticoder.org" link. Extremely helpful in understanding the various systems. But I'm still not understanding what the ECM is looking for to give me credit for a secondary air system "cold start". My secondary air pump runs for about 60 seconds then shuts off. My post catalytic converter Bank 1 and Bank 2 sensors show a slight drop in voltage during this 60 second period. The drop from 0.43 volts to 0.40 volts. Not sure if this is enough to tell the ECM the secondary pump actually ran. I just don't know what the ECM is looking for to validate the secondary air system is operating. I plan on testing the vacuum line to ensure it is calling for the check valve to open and I plan on testing the check valve using a vacuum pump. But if the O2 sensors are not providing a valid signal to the ECM to show secondary air system is operating, then I may need to change O2 sensors.

I have no fault codes and I have completed two FTP/Drive Cycles using cruise control on the freeway.

Appreciate all the help you can throw my way!
 
#18 ·
Thank you for the voltage of the pre catalytic O2 sensors. I'm hoping to receive some clarification on my questions regarding post catalytic O2 sensors and what the ECM is looking for when the secondary air pump is running. Hoping someone has the technical background with that kind of detail. I'm really trying to understand this system so I can make intelligent decisions on how to resolve it. This is my son's car and it's already past due on smog check. It passed the emissions with flying colors but failed on the engine monitors. So if I could understand how the ECM validates secondary air system performance, I would be able to troubleshoot this to the failed component, if there is one.
Anyone?
 
#19 ·
I assume you didn't fully understand the system judging by your two same questions on two different posts, so I will add a comment even though shanneba clearly gave you the answers and the references.

First of all, through away your assumptions that pos-cat O2 sensors are used for monitoring the secondary air system. As shanneba said pre- cat O2sensors are used for that purpose. Post-cat O2 sensors are used for checking the condition of catalytic convertors.

The purpose of the secondary air system is to inject more oxygen into the exhaust gas to aid further burning of unburned fuel during cold engine operation. That will in turn raise the temperature of catalytic convertor faster too (convertor is more efficient at higher temperature). When engine is cold (actually oxygen sensor is cold), DME can not do a closed loop fuel control because oxygen sensors do not operate properly (not reacting fast enough) until it reaches 600F ( that***8217;s why heated oxygen sensors are used for newer cars to promote faster heating of sensors and faster closed loop control.

During this open loop operation stage, the secondary air pump inject fresh air in the exhaust side for the purse mentioned before for about 2 minutes or so depending on surrounding conditions. DME monitors pre-cat o2 sensors to detect proper operation of the SAP system: it needs to see oxygen rich signal from O2 sensors because SAP is injecting fresh air (more oxygen) in to the system. For Bosch O2 sensors, 0.45V is stoichiometric air-fuel ratio (AFR=14.7 and lambda= 1). The sensor voltage bigger than 0.45V indicates a rich air-fuel mixture, and smaller than 0.45V for lean mixture (shanneba is wrong on that part). I need to verify with my measurement, but I think the pre-cat O2 sensors will have less than 0.2 V during SAP operation because the voltage curve of O2 changes very rapidly off from the stoichiometric air-fuel ratio as shown in the reference.

Also note that there should be no fault codes related the secondary air system for the monitor.

P0410 Secondary Air Injection System Malfunction
P0411 Secondary Air Injection System Incorrect Flow Detected
P0412 Secondary Air Injection System Switching Valve A Circuit Malfunction
P0413 Secondary Air Injection System Switching Valve A Circuit Open
P0414 Secondary Air Injection System Switching Valve A Circuit Shorted
P0415 Secondary Air Injection System Switching Valve B Circuit Malfunction
P0416 Secondary Air Injection System Switching Valve B Circuit Open
P0417 Secondary Air Injection System Switching Valve B Circuit Shorted
P0418 Secondary Air Injection System Relay "A" Circuit Malfunction
P0419 Secondary Air Injection System Relay "B" Circuit Malfunction
P1413 Secondary Air Injection Pump Relay Control Circuit Signal Low
P1414 Secondary Air Injection System Monitor Circuit High
P1420 Secondary Air Valve Control Circuit Electrical
P1421 Secondary Air System Bank 1
P1422 Secondary Air System Bank 2
P1432 Secondary Air Injection System Incorrect Flow Detected
P1453 Secondary Air Injection Pump Relay Control Circuit Electrical
P1454 Secondary Air Injection Pump With Series Resistor Control Circuit Electrical

http://www.bosch.com.au/content/language1/downloads/sensors_oxygenlsm11.pdf
 
#20 · (Edited)
It does look like I had the voltage wrong,

I based my voltage on the BMW document I linked, it shows the higher voltages as being lean on page 20.

Bosh Systems:
***8226; If the catalyst is operating efficiently, most of the
remaining oxygen in the exhaust gas is burned
(lack of O2 - "constant lean signal").
The sensor signal fluctuates slightly in the higher
end of the voltage scale.


I may try to record some pre and post cat O2 sensor signals after a cold start along with SAP state.
 
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