From: "Brom Kenneth (UA/AMA3)" <Kenneth.Brom@us.bosch.com>
To: "'David Cooley'" <n5xmt@bellsouth.net>
Subject: RE: Oxygen Sensors
Date: Wed, 12 Jul 2000 15:23:51 -0500
X-Mailer: Internet Mail Service (5.5.2650.21)
Hello Dave:
Thanks to your email, we discovered a design variation in our sensor
involving the grounding, that, depending on the ECU used by GM, would result
in the trouble you had.
We conducted a recall, re-engineer and re-distribution of the 15703 to
resolve any future problems in the field.
Best Regards,
Kenneth Brom
UA/AMA2
Robert Bosch Corporation
Broadview, IL.
708-865-5335
708-865-6433 (fax)
kenneth.brom@us.bosch.com
> ----------
> From: David Cooley
> Sent: Thursday, June 29, 2000 11:28 PM
> To: Brom Kenneth (UA/AMA3)
> Subject: RE: Oxygen Sensors
>
> Ken,
> Never heard back... What was the final outcome???
>
>
> At 05:35 PM 9/18/98, you wrote:
> >Hello David:
> >
> >Thanks for the detailed information.
> >
> >I will arrange for 2 extensive testing procedures to be performed on 2
> >sample OEM and Bosch sensors at our development facility in Farmington
> >Hills, Michigan.
> >
> >I would expect the process to take about 3 weeks, and I will keep you
> >informed.
> >
> >Thanks for your patience and understanding.
> >
> >Regards,
> >Ken.
> >
> > > ----------
> > > From: David A. Cooley
> > > Sent: Tuesday, September 15, 1998 12:10 AM
> > > To: Brom Kenneth (UA/AMA3)
> > > Subject: Re: Oxygen Sensors
> > >
> > > Hi Kenneth,
> > > Thanks for the quick response.
> > > Here is the problem I'm having...
> > > The original AC/Delco O2 sensor has the - output of the O2 sensor
> > > grounded
> > > to the shell. Mine had 80,000 miles and was getting very sluggish,
> > > mileage
> > > dropping etc, so I purchased the 15703. It is listed as a direct
> > > replacement for the 1995 Buick Lesabre vin code L 3.8 V6.
> > > I installed it and the car, as soon as coolant temp came up a bit,
> went
> > > full
> > > rich and the exhaust was billowing black smoke. I took it for a drive
> > > quickly to see if maybe the PCM just needed to learn the new Sensor's
> > > output... No luck. I figured then the O2 I was sold may have a
> problem.
> > > Using my Digital Volt Meter (>1Meg ohm/volt input impedance) I probed
> the
> > > sensor + and -... It was sitting at 980mV at idle and at 3500 RPM as
> well.
> > > I shut the car off and let it cool, then started it again and watched
> the
> > > output...
> > > Over about 30 seconds, it went from 0mV to 980mV again. I took it out
> and
> > > it was solid with soot. Put the old one in and the car started and
> ran
> > > fine... O2 volts hovered around 450mV but not very active... no more
> black
> > > smoke. Went and returned it for another 15703... Same problem. This
> time
> > > when I went to check the voltage, I probed from the sensors + lead to
> the
> > > engine block... I showed 1.98V!!!
> > > From the - lead to the block I showed 1.0 Volts. Removed it and
> checked
> > > resistance from the - lead to the Shell, and it was infinite (> 20Meg
> > > Ohms)... I checked the factory AC sensor, and the - lead was bonded
> > > internally to the shell. Putting the Bosch 15703 back in and adding a
> > > jumper from the - lead of the O2 to Ground made the car start running
> > > properly, and the sensor voltage was hovering around 450mV and VERY
> > > active.
> > > Mileage has come back to where I have been used to plus a bit better!
> A
> > > call to GM Tech support confirmed that the shell is supposed to be
> bonded
> > > to
> > > the - lead of the O2 sensor... It is isolated at the PCM and in the
> > > harness
> > > to eliminate ground loops.
> > > I went to the Napa autoparts store across the street from Autozone
> where I
> > > purchased the Bosch unit, and asked if I could check the Echlin and AC
> > > sensors they had in stock... Both had the - lead bonded internally to
> the
> > > shell.
> > > Just thought you might want this info for a production mod, or a new
> part
> > > specifically for this application.
> > >
> > > Thanks for your time,
> > > Dave Cooley.
> > >
> > > -----Original Message-----
> > > From: Brom Kenneth (UA/AMA3) <Kenneth.Brom@pcm.bosch.com>
> > > To: 'David A. Cooley' <n5xmt@bellsouth.net>
> > > Date: Monday, September 14, 1998 9:08 AM
> > > Subject: RE: Oxygen Sensors
> > >
> > >
> > > >Hello David:
> > > >
> > > >Thanks for contacting Bosch.
> > > >
> > > >Please feel free to contact me regarding your concerns with our
> Oxygen
> > > >Sensors, namely part number 15703 which you mentioned.
> > > >
> > > >Regards,
> > > >
> > > >Kenneth Brom
> > > >RBUA/AMA2
> > > >Bosch Broadview
> > > >708-865-5335 (ph)
> > > >708-865-6433 (fax)
> > > >kenneth.brom@pcm.bosch.com
> > > >
> > > >> ----------
> > > >> From: David A. Cooley
> > > >> Sent: Friday, September 11, 1998 12:24 AM
> > > >> To: bosch@sol.tins.net
> > > >> Subject: Oxygen Sensors
> > > >>
> > > >> Would like to know who I can talk to about a design flaw in at
> least
> > > one
> > > >> of the BOSCH aftermarket Oxygen sensors (P.N. 15703).
> > > >> Thanks,
> > > >> Dave Cooley
> > > >>
> > > >
> > >
>
> ===========================================================
> David Cooley N5XMT Internet: N5XMT@bellsouth.net
> Packet: N5XMT@KQ4LO.#INT.NC.USA.NA T.A.P.R. Member #7068
> We are Borg... Prepare to be assimilated!
> ===========================================================
>
>