[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: Climate control codes
Hairy green toads from Mars made Bob Kunz say:
> PS: All your climate controls must be working perfectly now and in the past.
> I know someone's got that list of error codes. Help!
Ask, and ye shall receive.
> From email@example.com Thu May 27 01:49:21 1993
> From: Eliot Lim <firstname.lastname@example.org>
> Subject: climate control hacking
> To: email@example.com (Quattro mailing list)
> Date: Wed, 26 May 93 22:40:45 PDT
lately i have been goofing around with the delco climate control panel's
debug mode. interesting discoveries.
to get into debug mode, press "outside temperature" and "off"
channel 7 is the most interesting. to get there, hit "warmer" 7 times.
the display indicates the state of the system.. i.e. which vents are
open, electric fan running, a/c compressor engaged etc etc.
i have not been able to get the system to recirculate with a/c on.
this is nice to have if the car in front of you is belching oil or
diesel fumes. setting "LO" temperature is supposed to do it, but
according to the display it doesn't. only recourse is "OFF"
i have not tried the a/c in cold weather, but in temperatures over
70F, the compressor and the electric fan runs continuously.
temperature regulation is achieved by (gasp!!) opening the heater
valve. no doubt the intent of this is to lower the interior humidity,
but being mechanically sympathetic i would have preferred the
compressor and fan to shut off periodically... ugh!!
the v8 doesn't have a voltmeter in the dash, but channel 11 is just
that. channel 12 counts the number of times voltage fell below 9.5
volts.. time for a new battery indicator. handy!
anybody know any hacks around the first 2 problems? this is the
second generation system found on the later cars. mine is a 1990 v8.
> From firstname.lastname@example.org Thu May 27 09:17:51 1993
> Date: Thu, 27 May 93 06:08:16 PDT
> From: Bill Samaras DTN 223-7322 <email@example.com>
> To: "firstname.lastname@example.org"@us1rmc.enet.dec.com
> Cc: email@example.com
> Subject: RE: climate control hacking
I have some answers...
>I have not been able to get the system to recirculate with a/c on.
>this is nice to have if the car in front of you is belching oil or
>diesel fumes. setting "LO" temperature is supposed to do it, but
>according to the display it doesn't. only recourse is "OFF"
You can force recirculation 2 ways. Either:
1. Turn the system OFF
2. Set the control to AUTO and the temp to LO. (This won't work in
BI-LEV). Be sure not to use the LO or HI fan buttons, as these
During normal operation, recirculation only occurs in AUTO mode when the
interior temperature is far above outside temperature.
>i have not tried the a/c in cold weather, but in temperatures over
>70F, the compressor and the electric fan runs continuously.
>temperature regulation is achieved by (gasp!!) opening the heater
>valve. no doubt the intent of this is to lower the interior humidity,
>but being mechanically sympathetic i would have preferred the
>compressor and fan to shut off periodically... ugh!!
There is a temperature sensor that will not allow the compressor or fan to run
when the outside temp is below ~40F. You are correct that warm air is blended
in with the cool air to get the correct temperature, but the compressor can
still cycle on and off. You may not see any cycling at idle, but it should
occur during normal driving. The graphic display on channel 7 will show that
the compressor is always on, but that is not the case. THe graphic display
shows that the compressor is enabled. Cycling is controlled by a separate
control system that includes a thermostat in the evaporator (to prevent
freezeup). The only way to know if the compressor cycles is to watch the
clutch. These cars have a "muffler" on the high pressure side of the
compressor circuit to absorb the shock when the compressor turns on. It is
hardly noticable that the compressor cycles. If you determine that the
compressor indeed never cycles, I'd suspect you are low on freon.
> From firstname.lastname@example.org Wed Dec 8 11:33:46 1993
> Date: Wed, 8 Dec 93 11:27:39 est
> From: email@example.com (Marat Spivak)
> To: firstname.lastname@example.org
> Subject: Re: STEAMED
> Can anyone shed light on a problem I'm having...?
> With the onset of cold weather, running the heater in my 89 100Q fogs up the
> window interiors. I don't smell antifreeze, so wonder if either there's
> residual water in the heater-core/air-conditioner box from a plugged drain,
> or if water can somehow make its way into that area during extended and
> heavy rain? Or...?
In addition, one other common failure that causes your symptoms may be a broken
fresh/recirc flap spring. The flap is moved to recirc position via vacuum,
and to fresh position via a spring. So, if the spring is broken, your system
could be running in recirc mode constantly.
To check for this condition, with engine running, turn the climate control
system off. This will cause the flap to close (recirc mode). Then, put
the system in Defrost, AUTO, or ECON mode, and set temp to LOW (or 64,
depending on your model). This should cause the flap to open (fresh mode).
If it does not open, your spring is probably broken.
o o| Marat Spivak, HyperDesk Corporation
o o| Suite 300, 2000 West Park Dr., Westboro, MA 01581
---+ E-mail: email@example.com (508) 366-5050 x145
> From firstname.lastname@example.org Wed Feb 15 18:45:46 1995
> Date: Wed, 15 Feb 95 13:46:23 PST
> From: email@example.com (Steven Buchholz)
> To: firstname.lastname@example.org
> Subject: Climate Control Diags (&RE: Recirculate Doors) - LONG
Before I excerpt the info on the "digital" climate control diagnostics,
I had a couple of things I wanted to note based on looking at the Bentley
manual ('84-'88 5000S/CS):
1 - There was discussion about the fan motor that blows air by the interior
temperature sensor. The discussion alluded to the motor being mounted
vertically. From the manual the motor appears to be mounted horizontally
under the dash. Furthermore, there is an exploded parts diagram on page
87.80 of the manual that implies that the motor has some type of splined
drive connector for the fan. If I had one of those babies go out I would
certainly look into repairing it myself or obtaining a non-factory
2 - It appears that there were a number of updates to the non-digital
climate control system between '85 & '86. Page 87.62 in the manual
discusses these changes.
The manual states that the digital climate control system was used start-
ing in November 1985. The control head is distinguishable from the older
system by the lack of the rear window defrost control and the addition of
a bi-level mode and override switches to set the fan at low or high. The
manual states that some faults are indicated w/o activating the fault
memory system. The LED next to the outside temperature button will flash
for ~1 min after a fault is detected or the ignition is switched on when
there is a fault. I wanted to note that the manual devotes 100 pages to
the digital climate control system. It includes detailed troubleshooting
flow charts as well as individual component tests. If you've got a real
problem it's probably best to obtain the manual. I'll include a discus-
sion of the fault check system here.
The fault system can be activated when the ignition switch is in the ON
position, the engine need not be running. The fault system is activated
by pressing the "ON" button while holding down the "OUTSIDE TEMP"
button. After activating the fault system the "OUTSIDE TEMP" button can
be released. When initially activated the numeric LED displays will in-
dicate a code of `01. This value indicates the "channel" that is select-
ed for monitoring. Notice that the Climate Control system will continue
to operate in the mode it was in before the fault system was activated,
and it is possible to terminate the fault system display by pressing any
button on the head other than the "WARMER" and "COOLER" buttons.
The fault channel selection will increment when the "WARMER" button is
depressed ... there are 23 fault channels. The fault channel value is
accessed by pressing the blue "COOLER" button. Once the channel has
been accessed it is possible to check other channels by pressing the
"WARMER" button. The channel definition is:
`01 System Faults (see fault code table below)
`03 Int Temp Sensor*
`04 Ext Temp Sens - Plenum*
`05 Ext Temp Sens - Radiator*
`06 *UNUSED* (But referenced on page 87.138!)
`07 Graphic Control Head Output
`08 Specified Temp Reg Flap Position
`09 Actual Temp Reg Flap Position
`10 Specified Blower Motor Voltage
`11 Vehicle Voltage <=== Useful for monitoring battery too!
`13 Ambient Temperature Switch
`14 *UNUSED* (But referenced on page 87.141!)
`15 Kickdown switch (auto tranny)
`16 Engine Coolant Overheat switch
`21 AC ON signal
`22 # of low voltage occurrences
* - Readings from these channels are an encoded 3 digit value that are
decoded using a table in the Bentley manual.
System Fault Codes for channel `01
00 - No worries mate!
`01 - Interior temp sensor open
`02 - Interior temp sensor shorted
`03 - Exterior temp sensor in plenum open
`04 - Exterior temp sensor in plenum shorted
`05 - Exterior temp sensor in front of radiator open
`06 - Exterior temp sensor in front of radiator shorted
`07 - Motor for positioning heater flaps in programmer NOT OK
`13 - Battery voltage less than 9.5v
`14 - High pressure sensor - Excess pressure in system
`15 - High pressure sensor - short circuit
Definitions for graphic control head output - channel `07
(Imagine the 2 7-segment LED displays adjacent to each other)
H G A-Radiator Cooling Fan Stage 1
| | B-A/C Compressor ON
v v C-Temp flaps toward cooler position
==== ==== D-floor vents open
A==> / / / / <==F E-BI-LEVEL (center & floor open)
/ / / / F-center vents open
===== ===== G-A/C Recirculation door closed
B==> / / / / <==E H-Temp flap toward warmer position
/ / / /
Testing air control doors - the diagrams on pages 87.127 & 87.128 show
the actuator connections for the climate control. If the diagram is
correct, the same line that selects outside air or recirculated air
controls the flow of coolant to the heater core. The table below shows
actuator positions for several conditions.
Function | FRESH/RECIRC | CENTER VENT | DEFR/FOOT | HEATER VALVE
OFF | RECIRC | CLOSED | WINDSHIELD | CLOSED
ECON 64F | FRESH(?) | FULLY OPEN | FOOTWELLS | OPEN(?)
ECON 84F | FRESH | CLOSED | FOOTWELLS | OPEN
BI-LEV 64F | FRESH(?) | HALF OPEN | FOOTWELLS | OPEN(?)
BI-LEV 84F | FRESH | HALF OPEN | FOOTWELLS | OPEN
AUTO 64F | RECIRC | FULLY OPEN | FOOTWELLS | CLOSED
AUTO 84F | FRESH | CLOSED | FOOTWELLS | OPEN
DEF | FRESH | CLOSED | WINDSHIELD | OPEN
Notice that I question a couple of the entries in the table in regards
to the heater valve being opened when the temperature setting is low.
I'm noting that here, because the heater valve servo and fresh air/recir-
culate servos are connected together. One important thing to note is
that the recirculate/fresh air door has only two valid positions ... if
yours appears to be somewhere in between it is an obvious fault. BTW,
the heater valve servo is open when the actuator arm protrudes from the
vacuum motor and the valve is closed when vacuum is applied to the motor.
> From email@example.com Thu Feb 23 14:54:58 1995
> Date: Thu, 23 Feb 95 11:27:36 PST
> From: firstname.lastname@example.org (Steven Buchholz)
> To: email@example.com
> Subject: More 5k Climate Control Stuff
Did the fresh air/recirc flap fix last night on the '88 5kCSQ, so I wanted
to give a quick report to the net about the experience. I had received the
Tech Bulletin by fax from Linda@Carlsen (Group 87 Number 90-01 Date
11/30/90). It states that it applies to '84-88 5000s & 100/200s from '89.
The procedure calls for removing the glove box and glove compartment liner.
In addition, I found it useful to remove the plastic airbox cover over the
A/C & blower in the engine compartment behind the firewall (which means
removing the right windshield wiper).
The problem with the car was that the plastic mount that held the vacuum
motor in place had broken, as had the flap return spring. The TB states
that the mount breaks due to a shifting of the seal, causing the adhesive
to seal the recirc flap shut. I did find that the recirc flap seal had
shifted (but the fresh air flap seal had not !?). The replacement bracket
is a pretty substantial piece of bent metal that gets screwed into the
remaining plastic rails with two self-tapping screws. If both flaps are
removed the location can be accessed from above or below, but I found that
it was more easily accessed from the passenger footwell. The procedure
states to attach the bracket with a certain self-tapping screw. The screw
that is called for has a "Phillips" head ... which is quite difficult to
attach, even with a stubby screwdriver. I would recommend getting two
self-tapping sheet metal screws with the 1/4" hexagonal head and a flange
to keep it from sliding into the socket. If I used them I could have used
a ratchet to attach the bracket. I also pre-drilled small holes in the
plastic (by twisting the drill bit between my fingers) to minimize the
chance of breaking the plastic and making the screws easier to start.
I did buy a replacement vacuum motor because I knew that there was a leak
in the line, but I found that what had happened was that the line got pulled
off the motor when the bracket broke. The motor was in acceptable shape,
but I replaced it anyway. I'd recommend that the part not be purchased
before the operation ... wait to see if you need one first.
Since the spring had broken and there was no explicit diagram either in the
procedure or the Bentley, I had to guess where it was supposed to attach.
I connected it to a horizontal plastic bar that went between the same mount-
ing rails that hold the vacuum motor (there were no other candidates).
Attaching the spring to the recirc flap was one of the more difficult parts
of the process! I recommend having a 6mm allen wrench handy to help with
R/R of the vacuum motor and the spring.
Thanks to Carl DeSousa for working out the cost+20% at Carlsen! This whole
project cost ~$30 including the replacement vacuum motor! It took me be-
tween 3-4 hours to perform.
Andrew L. Duane (JOT-7) firstname.lastname@example.org
Digital Equipment Corporation (603)-881-1294
110 Spit Brook Road http://www.zk3.dec.com/~duane
Nashua, NH 03062-2698
Only my cat shares my opinions, and she's a pack-rat, too.