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Homer
Guest
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 Posted:
Thu Dec 01, 2005 9:13 am Post subject:
1990 525i RPM sensor |
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Greetings and salutations,
I have some questions about my 525i.
First a little background:
My 525i stopped running last week. I have the Bently Service Manual and have
been going through troubleshooting a no-start condition. Ignition components
appear alright, however there is no spark. The manual instructed checking
the resistance of the Crankshaft/RPM sensor. The ilustration in the manual
shows that wires 1 & 2 go through a coil and should have 540 ± 10% ?
resistance. Connector 3 shows that it is grounding a shield surrounding
wires 1 & 2. There is an open circuit between the number 3 connector and the
metal body of the sensor.
My questions are:
Should there be continuity between the number 3 connector and the sensor
body?
Could this cause the no start condition?
What else is a common cause of a no-start condition?
Thanks in advance,
Homer
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Dave Plowman (News)
Guest
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| Posted:
Thu Dec 01, 2005 10:14 am Post subject:
Re: 1990 525i RPM sensor |
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In article <bDujf.28940$tV6.2595@newssvr27.news.prodigy.net>,
Homer <hbrinlee@hotmail.com> wrote:
| Quote: | Connector 3 shows that it is grounding a shield surrounding wires 1 &
2. There is an open circuit between the number 3 connector and the
metal body of the sensor. My questions are: Should there be continuity
between the number 3 connector and the sensor body?
|
It wouldn't surprise me if it were only grounded at the ECU end - two
grounds can cause loops and add to the interference rather than help stop
it.
--
*INDECISION is the key to FLEXIBILITY *
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound. |
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Psycho
Guest
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| Posted:
Fri Dec 02, 2005 9:13 am Post subject:
Re: 1990 525i RPM sensor |
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On Thu, 01 Dec 2005 10:14:08 +0000 (GMT), "Dave Plowman (News)"
<dave@davenoise.co.uk> wrote:
| Quote: | In article <bDujf.28940$tV6.2595@newssvr27.news.prodigy.net>,
Homer <hbrinlee@hotmail.com> wrote:
Connector 3 shows that it is grounding a shield surrounding wires 1 &
2. There is an open circuit between the number 3 connector and the
metal body of the sensor. My questions are: Should there be continuity
between the number 3 connector and the sensor body?
It wouldn't surprise me if it were only grounded at the ECU end - two
grounds can cause loops and add to the interference rather than help stop
it.
|
When my 89 325i stopped running, this was the culprit. One of the
wires had broken right at the sensor and was making intermittent
contact. Real pain in the ass before I happened on the actual
problem...
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Homer
Guest
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| Posted:
Tue Dec 06, 2005 1:39 am Post subject:
Re: 1990 525i RPM sensor |
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<snip>
| Quote: | What else is a common cause of a no-start condition?
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Thank you all for your kind replies.
Another fact that I failed to include in my OP is that the code reader
(scantool) I bought from an Internet site displayed an "E" when I ran the
diagnostic command to retrieve any trouble codes that may have been stored
in the car's computer.
A normal display has always been "--" in the past when no codes were found.
The "E" code was not listed in either the Bently manual nor the scantool
user's manual.
A call to the vendor of the scantool failed to define the "E" code.
Dave Plowman advised that the isolated shielding in the disconnected RPM
sensor could be normal.
The only other sensor displayed in the circuit diagram was the #6 Cyl
sensor.
I had recently replaced the sparking plug wires (they included a new sensor)
so I assumed that it was not a part of the no-start problem.
The Bently manual suggested (in the maintenance section) that owners of
1989 -1995 5 Series BMWs should always carry a spare DMI main relay.
I purchased one from the local dealer for $21 UDS and installed it in the
underhood electrical box.
The engine started thereafter and there has been running really well since.
The car keeps burning out other seemingly unrelated fuses such as the power
mirrors and A/C, so I know that there are other issues yet to resolve, but
at this point I can drive to work to earn money towards additional repairs.
Thaks again,
Homer |
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