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1999 528i
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7 Posts
Discussion Starter · #1 ·
Had car checked out and not sure if this will be expensive, I am not familiar with a wheel speed sensor or selonoid for transmission. Is the anyone having a problem to with a 1999 528i when 3rd gear shifts into drive there is a extreme knock. Any info is helpful!
 

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Under the lift arms
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13,381 Posts
:( automatics kinda suck cause of this.... tranny codes help with diagnostics but do not pin point the problem...

and wheel sensors tell your abs computer and ecu whats going on @ the wheels... nothing more...


with this description it could be about 20 different problems
 

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Seek to understand,^Value
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25,199 Posts
wheel speed sensor or selonoid for transmission
I don't know anything about the transmission but each of the four wheel speed sensors is trivial to test.

I just did a /wheel speed sensor(F3) in the bestlinks to find:
- How to test your wheel speed sensors (1)

There are six tests (that we know of) for the wheel speed sensors (as noted here).

UNDERSTAND WHEEL SPEED SENSORS:
Note: The wheel speed sensors are two-wire hall effect transducers which send a digital square wave signal with a low of .75 volts and a high of 2.5 volts to the DSC control unit. Each sensor receives a well-regulated 8 volt power supply from the control module through one wire. The ground path for the sensor is through the second wire back to the control module. The signal is generated by a pulse wheel affecting the voltage flow through the hall element in the sensor. The pulse wheel is integrated into the wheel bearing assembly, behind the seal. This protects the trigger wheel from foreign substances which may affect the wheel speed signal.

TEST WHEEL SENSOR CIRCUIT FROM THE ABS CONNECTOR
(also checks wiring circuit):
OPTIONAL: Jack car up (so that all four wheels can be spun to test voltage & resistance fluctuations of the hall-effect sensors)
- Turn the car off and remove the key from the ignition.
- TEST 1: Switch the DMM into the diode test position
- Wrap a stiff 20AWG wire onto the ends of your DMM probe for sticking into ABS-connector pins
- Label the positive 20AWG wire with white tape so that you won't get confused as you switch back and forth
- Stick the ends of the wire into the appropriate female holes of the ABS connector (13-29, 30-31, 28-12, 15-16)
- In one direction, you should see 1.7 to 1.8 volts (note the pinouts mentioned are in order, positive to negative)
- In the other direction, you should see OL or some other infinite reading (open circuit)
- TEST 2: Switch the DMM into resistance checking mode (optional)
- You should see around 3.3 Mega ohms in one direction & approximately twice that in the other direction (but some say more)
- TEST 3: If desired spin the wheel at about 1 revolution per second, by hand (the resistance should fluctuate as the wheel spins)
- TEST 4: Switch the DMM into millivolt mode (optional) & again spin the tire & wheel assembly by hand (test-lead polarity won't matter)
- You should read between 1 and 5 mV when you spin the hub (no voltage implicate the sensor or circuit)
- OPTIONAL TESTS BELOW REQUIRE FLYING LEADS WITH THE IGNITION SYSTEM ABS SYSTEM CONNECTED & POWERED UP:
- TEST 5: Swith the DMM into the 10v and attach flying leads to the sensors with the power on
- You should see the voltage going to the sensor and the return signal
- Expect a baseline voltage of about +5 to +12 volts depending on the ABS system (does anyone know this value?)
- Expect that baseline voltage to the sensor to change (by how much?) as you spin the wheels
- TEST 6: Hook an oscilloscope with "flying leads" to the ABS sensors (notice that the ABS system must be powered)
- You should see nice clean square waves generated as you hand spin the wheels at about 1 revolution per second.
Note: The oscilliscope can detect problems that can't easily be found with a DMM (A scope pattern for a wheel speed sensor should show a classic sine wave alternating current pattern that changes both in frequency and amplitude with wheel speed. As the wheel is turned faster, signal frequency and amplitude should both increase. Damaged or missing teeth on the sensor ring will show up as flat spots or gaps in the sine wave pattern. A bent axle or hub will produce an undulating pattern that changes as the strength of the sensor signal changes with every revolution. If the scope pattern produced by the sensor is flattened (diminished amplitude) or is erratic, it usually indicates a weak signal caused by an excessively wide air gap between the tip of the sensor and its ring, or a buildup of metallic debris on the end of the sensor. A weak signal can also be caused by internal resistance in the sensor or its wiring circuit, or loose or corroded wiring connectors.)


INTERPRET DIODE-TEST RESULTS:
- If the DMM, in diode mode, reads infinity ("OL") in both directions, you've got a bad sensor or circuit
- If the DMM, in resistance mode, reads much greater than 7Mohms, you've got a bad sensor or circuit
- If all 4 sensors read OK, it's most likely the ABS control unit.
- If you think you found two bad sensors, you probably messed up.
- Rarely is the cause due to bad steering angle (yaw/lew) sensors
- Rarely is the cause due to a bad hydro unit
- The problem is almost always a wheel rotation sensor or the ABS control unit

ACTUAL RESULTS ON MY 2002 E39 THIS MEMORIAL DAY WEEKEND:


DOUBLECHECK WHEEL SENSORS AT THE WHEEL:
Note: You can run this test w/o removing the wheel but access to the sensor connector is easier with the wheels off the E39
- If one or more sensor circuits test bad in any of the three tests above ... then ...
- Locate the sensor blue connector in the rear of each front wheel well by turning the front wheels
- Easiest to first locate the sensor (bolted on the wheel carrier near the hub) and trace its wire back to a black plastic hinged box housing
- Open the locked hinged plastic rectangular black box with a small flathead screwdriver
- Locate the blue wheel sensor connector (next to a black brake wear sensor connector)
- Pull the blue wheel sensor connector out of the box and disconnect the two sides
- Re-check the sensor there with the diode function of the DMM



CHECK WHEEL SENSORS OFF THE VEHICLE:
- If any sensor still checks bad, pull the sensor off the vehicle for a closer inspection
- Chock wheels and jack E39 BMW and jack stand at the 4 jack pad locations
- Remove 4mm allen head bolts to sensor retention screw (two retaining bolts for fronts, 1 bolt for the rears)
- Pull wheel sensor out of hub assembly, straight up.
- Clean with CRC electronic cleaner
- Check with DMM diode-test meter as before
- Grease with Staburags NBU 12/K or equivalent grease
- Replace sensor back into hub assembly, snug tighten to 6 foot pounds
- Replace rear wheel, tighten to 82 to 96 foot pounds
Note: You might wish to swap sensors on the same axle when replacing so as to obtain further diagnostic information should an anomaly occur.
Note: Here is a picture of a dirty and cleaned sensor (magnetic particle buildup)

 

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Under the lift arms
Joined
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13,381 Posts
wow..bumble bee.... you just pulled out the A card.. with the quickness.... That is most defiantly the diag tree


theres a couple of cheats here and there, but thats it right there
 

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1999 528i
Joined
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7 Posts
Discussion Starter · #5 ·
Wow! This is helpful

Thank you all for the reply but the question I have is why do I feel a knock when it shifts from 3rd to drive? Is that normal? How about the transmission solenoid, is this can be a problem too and expensive. I would love to do the work myself, but uneducated at mechanical work so I have to pay someone or find a transmission shop.
 

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Seek to understand,^Value
Joined
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25,199 Posts
How about the transmission solenoid
With a bit of frustration, I must say that your first duty (before asking) is to do a search (same as it is for all of us), and then to summarize what you found ... and then to ask your question.

Anyway, I did a quick search for "transmission solenoid" in the E39 forum and found these which may have useful information for you. (If they are useful to you, let us know; if they don't provide useful information, please tell us why not.)

- Strange TCC issue
- Transmission Safe Mode... huh?
- E39 Transmission Pressure Control Solenoid P0963
- 540i E39 transmission
etc.
 

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1999 528i
Joined
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7 Posts
Discussion Starter · #7 ·
Had a Mechanic Look at car

Apparently I need a Mass Airflow sensor and I swear this mechanic is trying to rob me blind. He wants to supposely order the part from the dealer at a cost $400-$500. Is this true??? This is what the invoice states:

Diagnose then report, hard shift to third bad noise
Symptom: Diagnose Symptoms, Codes
153, 227, 228, 202, 203, 149, 8
Codes are referring to Mass Airflow Problems,
Tested Mass Air flow sensor and it fails most of the time. A bad Mass Air flow sensor can cause the transmission to shift improperly, We need to replace the Mass Air flow sensor and then Retest the Transmission.

What the heck are these codes and how do I look them up??? Help anyone!
BTW, where can I get the Mass Air flow cheap??? :mad:
 

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Seek to understand,^Value
Joined
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25,199 Posts
Apparently I need a Mass Airflow sensor and I swear this mechanic is trying to rob me blind. He wants to supposely order the part from the dealer at a cost $400-$500. Is this true???
You can clean and test the MAF and even replace it yourself far cheaper:

From a quick /MAF(F3) in the VERY best of E39 Links:
- Mass air flow sensor (MAF) and idle control valve (ICV) require periodic cleaning (1) (2) & buying a replacement MAF cheaper than the BMW MAF (RangeRover MAF) (VW MAF) (Hyundai MAF)

 

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Seek to understand,^Value
Joined
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25,199 Posts
What the heck are these codes and how do I look them up???
I'm getting a little tired of looking up links for you that you can look up yourself, especially as there is no indication you're actually reading them ... so here's my last lookup for you.

All the codes you need are in this PDF from RDL in the best links thread:
- All OBDII codes, including BMW-specific P1xxx DTCs specific to the engine computer of each BMW (1) (2)
 

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1999 528i
Joined
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7 Posts
Discussion Starter · #10 ·
Sorry Blueblee

Blueblee, thank you for truly helping me. I am very new to this and I am a female! I don't have men in my home to help understand any of this. So, I really thank you! You have been a good help. :thumbup:
 

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wannabe DIY'er
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332 Posts
The problem you describe might be due to a bad MAF, that has been documented before. $500 sounds 2-3 times more than it should though. I would not let your mechanic order that part, search online and order it yourself. It is so incredibly easy to replace that I know you can do it yourself.
 

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1999 528i
Joined
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7 Posts
Discussion Starter · #12 ·
More confused

Now Bluebee I followed the directions you leading me. With Mass Air Flow start with a cleaning, this morning I go start the car just for a morning start and WILL NOT START! I have not had the chance to clean the air flow. Could be my O2 sensor bad too?? You can yell at me Blueberries, I will tale that. The forms for for the Mass Air Flow replacement does not state the model for BE that shared the same Mass Air Flow. Can you point me in that direction?? Model and year would be great.
 

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1999 528i
Joined
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7 Posts
Discussion Starter · #13 ·
Wow, I did it..

Went and messed around with the car because I feel I can do this. I learned if I unplug the Mass Air Flow and be damn, the car started up. I personaly went O'Reilly's Auto and scanned for codes. One code appeared P0101 and highlighted Mass Air Flow Sensor. I am not sure if I should purchase the sensor there but the pric is $219. Is it okay to purchase the sensor there or somewhere else??? I just need the answer to this question I am done. With the information from Bluebee I can change the sensor myself. :thumbup:
 
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