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Hello. I've been struggling with the cruise control on my wife's '93 940 wagon (automatic transmission). When we first got the car a little over a year ago (we replaced our first 940 wagon after being rear-ended and totaled at 250,000+ miles). At first the system would engage, but lose speed gradually and I got it down to an tired brake pedal switch/valve. I took apart the switch and attempted a fix by adding a bit of dielectric grease around the o-ring. That helped for a while and the cruise control worked perfectly for about a month. Then started doing its thing of loosing speed again and then stopped engaging all together. I finally got around to doing a more permanent repair on the vacuum valve at the brake pedal. I took it apart again, cleaned out the dielectric grease from before, made sure everything is clean and dry, then applied two layers of plumbers' Teflon tape to the plunger and reassembled. I checked it with my mity vac and the switch holds 15 psi indefinitely now. I re-installed it, checked the vacuum lines by unplugging the T at the vacuum pump and connecting the mity vac to it instead. I applied some vacuum and observed the servo pull the throttle all the way in and hold it for a long time without loosing any vacuum (according to the gauge on the mity vac). So, my plumbing is good. Went for a ride, no engagement at all from the cruise control. My brake lights are working fine, my speedometer works fine. I performed diagnostics on B2 after driving over 22 mph and got no codes (1-1-1) on mode 1 and all the proper codes on mode 2 except for the 1-1-3. I have no idea how to activate that one. I think that possibly it's for manual transmission. I have not tested the pump itself, I guess. How do I do that? Everything else seems fine. The pump did work a while back when I got engagement, but lost speed due to the leaky brake pedal valve.
Any help would be appreciated!
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Vladimir. '98 S70 base, 5-speed manual - his, '93 945 - hers
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Well, I finally got the cruise control working. The problem was a broken wire in the turn signal stalk.
In one of my earlier posts in this thread I mentioned that I was not getting the 1-1-3 code and I thought it was because I do not have a clutch switch (automatic car). Well, 1-1-3 code is very important, it turns out. The FAQ was not very clear on how to test it. It says: "Depress brake then clutch pedal for a second" in the action column. Well, if you do that you will get the brake pedal code, 1-3-2, which is what I got. Turns out the 1-1-3 code is generated every time the switch goes from ON to OFF and from OFF to ON. This was not at all clear. The FAQ should say in the action column: "Move the selector switch from ON to OFF or from OFF to ON" to obtain 1-1-3 code. Also, in the Fault column it says: "if no code:brake and clutch valve" This is incorrect. No 1-1-3 code means no power to the control module. I was able to learn that in the cruise control diagnostic procedures for 850, which is similar enough to have helped. This is the link to the PDF with 850 diagnostics: http://www.volvoclub.org.uk/tech/service/850/CruiseControlSystem.pdf
1-1-3 was the only code I was not able to get in the diagnostic mode 2 (socket B2).
So, it took me a long time to arrive at this. I suspected the control module, so I removed it, opened it, examined it and found nothing suspicious like burned components or traces. I saw a relay there and traced the switch to the yellow/red wire in the connector, which is the wire going to the vacuum pump's bottom wire. That is supposed to be +12V. I had nothing on that wire. I soldered some wires to the control module such that I could drive and have my voltmeter connected to the vacuum pump +12V. I drove and tried setting the cruise control and got zero on that terminal. This led me to thinking I was not getting power to the module's vacuum control circuit. That's when I started looking more into the 1-1-3 code and found the 850 diagnostic routine that explained it a bit better than our FAQ. It clearly says that 1-1-3 code is produced when the selector switch is moved from ON to OFF or from OFF to ON. I did not get that and that's when I took the shroud around the steering wheel off and saw the broken blue/green wire staring at me. It was broken right at the edge of the plastic covering the stalk, but I was able to strip enough of it to be able to solder it back and apply some shrink tubing to the solder joint. As soon as I did that I got the 1-1-3 code and the test drive confirmed perfect operation of cruise control. My repair of the pedal valve with teflon tape is working very well so far. I went up a hill that caused the cruise control to slow way down before it died all together (from the broken wire). So far so good. I buttoned everything up and all seems well with the cruise control.
Whew! That was a hard one. Mainly because I was misled by the FAQ's explanation of the diagnostics. Is there a way to change the FAQ to be more clear? I would be more than happy to do it.
--
Vladimir. '98 S70 base, 5-speed manual - his, '93 945 - hers
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Vladimir, super diagnostic work. Mea culpa on the FAQ: I had no idea this was incorrect. I made the change. Thanks for your persistence and contributions.
Steve
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See the 700/900 "FAQ" at the menu bar top screen left side.
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Steve, thanks! So far I see the same OLD entry in the FAQ. I made a post a few minutes ago detailing the diagnostic process. Feel free to use all or part of it to insert into the FAQ.
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Vladimir. '98 S70 base, 5-speed manual - his, '93 945 - hers
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I made the change to the new FAQ which is to be uploaded in about a month.
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See the 700/900 "FAQ" at the menu bar top screen left side.
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I see. Perhaps we should adapt more of a Wiki type environment where updates can be a little more immediate.
In any case, thanks for maintaining the FAQ. It has been a gold mine for me over the years. I've owned two '93 945's since 2003. The first one had close to a quarter million miles on it when it was rear-ended and totaled almost two years ago. This one is almost the same car of different color and slightly more spartan trim (cloth vs. leather, no sunroof, etc.). I was lucky to find it with 125K on the clock last year. It is so familiar now that it takes me fraction of the time to do the usual ball joints, sway bar links, control arm bushings, water pump gaskets, etc on it. Very predictable and the FAQ demystifies those predictable failures, which is very heartening.
Thanks again to everyone.
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Vladimir. '98 S70 base, 5-speed manual - his, '93 945 - hers
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Agreed, but the FAQ started before wikis were even invented. We're stuck with it.
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See the 700/900 "FAQ" at the menu bar top screen left side.
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You are right. It's easy to forget that most of our cars are older than Wiki and some are older than internet itself.
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Vladimir. '98 S70 base, 5-speed manual - his, '93 945 - hers
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Dear Vladimir,
Hope you're well. See e-bay item #390660610879. This unit seems to be in good shape: the factory markings on it are clean and bright.
Hope this helps.
Yours faithfully,
Spook
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Dear Vladimir,
Hope you're well. I'll nominate you for the Sherlock Holmes award!!!
Your research shows that when cruise control malfunctions: (a) vacuum pump and cruise control module not likely to be a source of trouble; (b) throttle servo (black rubber bellows) and vacuum lines merit a quick look; (c) turn signal wiring and cruise control switches on the turn signal stalk should be checked first, as it is easy to access.
Yours faithfully,
Spook
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Spook, thanks for the award nomination. I must say that the diagnostics
built into the cruise control system are very good. Had I been aware of the
1-1-3 code not showing up because of a problem and not because of the
ambiguity in the description, I would have been done with this fix a day
earlier. So, I will second your evaluation of the troubleshooting cruise
control with the following augmentation.
1. Check the vacuum system integrity first. Disconnect the "T" connector at
the pump and apply vacuum to it using something like a mity vac. Observe
the servo at the throttle contract, pull back the throttle cable and hold
it there for a few minutes. If this checks out proceed to 2. Otherwise find
the source of a leak in the vacuum system. Mine was in the brake pedal
switch, which I guess is common. I found my vacuum pedal switch/valve to
not hold vacuum. Removing the switch and disassembling it revealed the
o-ring not fitting the plunger snugly. I wrapped two layers of teflon tape
on the plunger and reassembled. This fixed the vacuum problem. I then
retested and the vacuum held.
2. Perform OBD tests regarding the cruise control. To do this, connect the
fly wire from the diagnostic block A to socket 2 on diagnostic block B.
Turn the ignition to "ON" position and ress the button on the block A for
one second. If the code comes back as 1-2-2, things most likely are okay.
This code means the signal from the speed sensor has not been received.
It's not a failure yet since the system erases the codes every time the
ignition is turned off and when you turn it back on the initial status is
no signal from the speed sensor since that only comes once the speed
exceeds 22 MPH. If you leave the diagnostic connected and go for a ride and
then perform this test BEFORE you shut down the ignition the code should
come back 1-1-1. If it does not then the code table in the FAQ should be
used to identify the issue. If the code comes back 1-1-1, then everything
is fine with this test and you should proceed to mode 2 of this test. Mode
2 is where you can check the various electrical controls such as the turn
signal stalk buttons and sliders as well as the brake light and neutral
cut-off switch. To do this test turn the ignition to "ON" and connect the
diagnostic wire to B2 as in mode 1. But this time you press the button
twice holding it down for about a second each time. The light on the
diagnostic block will start blinking rapidly. This means you are in mode 2.
While the light is blinking rapidly slide the cruise control selector from
ON to OFF or from OFF to ON, it really doesn't matter for this test. As the
selector transitions from ON to OFF or OFF to ON, observe the light on the
diagnostic block. It should stop blinking rapidly and issue a code of
1-1-3. If no code at this point, then the stalk switch is likely at fault.
This was the case with me. The FAG is a bit misleading on this. It states:
"Depress brake then clutch pedal for one second" for this test. This is
incorrect to get 1-1-3 code you need to move the cruise control selector on
the turn signal stalk from OFF to ON or ON to OFF. If 1-1-3 appears, then
the light starts to blink rapidly again, then the system is ready for the
next test. The order of these tests is irrelevant. The next test could be
the RESUME function of the selector switch. Start with the selector in ON
position. While the light on the diagnostic block is blinking rapidly slide
the selector to RESUME and let go. The rapid blinking should stop and code
1-2-3 should be issued. If no code, again, suspect the turn signal stalk.
Next test the SET function. While the light is rapidly blinking press the
SET button on the turn signal stalk. Code 1-3-1 should come out. If not,
again, the turn signal stalk wiring is suspect. If all these tests pass
then go on to the brake light switch test. While the diagnostic light is
blinking rapidly press the brake pedal. Code 1-3-2 should be issued. If no
code here, check the brake light switch. Lastly the Start inhibitor switch.
While the light is blinking rapidly shift the transmission to neutral. Code
2-2-3 should come out. I belive this is only for automatic cars. If you
have a manual transmission you would perform a clutch test much like the
brake pedal test. My car is automatic and I can't say from experience how
to test the manual.
If any of the codes did not show up, there is an electrical problem and
should be followed up. If the three codes corresponding to the turn signal
controls do not show up, remove the shroud around the steering wheel (two
small torx screws on the top and two slightly larger torx screws on the
bottom) and gain access to the turn signal stalk wiring and examine it.
Mine had a broken blue/green wire right at the point where plastic of the
stalk ends. The wire was broken very close to the edge of plastic, but I
was able to strip enough of it to solder it back and apply some shrink
tubing. I really did not feel I needed to spend money on the new stalk. If
I had no been able to solder as it was, I would have cut the plastic around
the stalk a little to get a bit more length on the broken wire. However, I
was successful in soldering it the way it was, so the fix was simple.
Diagnostics were troublesome because of misleading FAQ about the 1-1-3
code. Perhaps part or all of this post can be used to fix the FAQ. As of
this moment it is still the way it was.
3. If all the above checks out good, then I would test the vacuum pump by
applying 12V to the bottom terminal and GND to the middle and top terminals
at the same time. This should activate the pump and the vacuum control
valve at the same time and cause the servo at the throttle to contract
(remember to re-connect the "T" to the black nipple on the bottom of the
pump, the white nipple is vent to atmosphere and should be left open). If
the GND is removed from the middle, but left on the top terminal the servo
should stay contracted and hold vacuum.
4. If everything checks out to this point then it's time to question the
control module, but so far I am not sure if there is even a single
confirmed module failure reported in the community.
Thanks again to everyone who tried to help.
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With regards to your number 4 above, I did have a bad control module as stated in my earlier post. The bad control module problem was intermittent and worked maybe 25% of the time and since I changed it 4 years ago or so, the cruise has not failed once.
I might have missed it, but did you fix the stalk or get another one. I think the way the wires lay by the end of the lever is important. They shouldn't be pinched.
So, I would say that the main cause of problems with the cruise, in order of most common, is the pedal switches, then the hose being knocked off the vacuum pump, then the stalk, then the cruise control module, then the vacuum pump IMHO.
--
Mine: 4-940s running, 2-740 and 1-940 parts cars, and 3 1959 John Deere 630s (1 for parts), dtr1:3-940s, dtr2:1-740
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Sorry, I did miss that you had a bad module. I opened mine up and examined it thoroughly and found nothing visually. Everything in there looked like new. It's a pretty complicated module with what looks like a micro-controller (Toshiba chip), supporting logic and a relay for the pump. I was able to trace the relay contacts to the pump under the hood and from that work I was able to activate the pump and the vacuum controller through the module connector. The wires are the same color on the connector as on the pump as the harness goes directly between the two pieces. In any case, the relay looked perfect and contacts were not carbonized and the rest of the module (two PC boards) looked clean and no burnt smell in it or failed solder joints or broken traces. Looks like a robust unit. No wonder it fails infrequently.
I was able to repair my turn signal stalk without removing it. The wore broke right at the end of plastic and I had very little to work with, but I was able to strip about 1/16" of insulation on either side and solder them together. I also put a piece of shrink tubing on the joint. It's not a pretty fix, but it works and if it fails again, I will remove the stalk and to a better job of it. I did not feel the need to buy new stalk at $150 or so for one broken wire.
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Vladimir. '98 S70 base, 5-speed manual - his, '93 945 - hers
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All of this went into the new FAQ... with gratitude.
Steve
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See the 700/900 "FAQ" at the menu bar top screen left side.
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I am not sure about the teflon tape wrapped around the plunger. It may not allow the plunger to operate correctly. I repaired mine with a new O ring (left over from an AC O ring kit). It fixed the same symptoms as you started with.
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I tested the pedal switch by applying vacuum at the pump using mity vac and
then stepping on the brake pedal and observing the vacuum bleed off. Mity
vac has a vacuum gauge, so I pumped about 15 psi of vacuum, which pulled
the throttle all the way back. When I tapped the brake pedal the vacuum
bled off and the throttle returned to its normal position. I think the
pedal switch works really well at this point. I left the vacuum on for a
while and when I came back it was still there until I tapped the brake.
I believe my problem is in the module somewhere. I don't think I am getting
activation signal to the pump. I will try to make an LED light fixture to
observe the pump signal tomorrow. A known good spare module would be really
nice to have right now.
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Dear vladimir,
Hope you're well. Your last sentence is problematic. The vacuum pump - a black plastic unit, mounted on the engine compartment wall (driver's side, North American models) below the strut tower - rarely fails. When you said it "lost speed", how did you ascertain this? You might want to clean the connections to the vacuum pump, as they are more likely to be a source of intermittent operation, than is the vacuum pump itself.
Hope this helps.
Yours faithfully,
Spook
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Hi and thanks for the reply. Let me try to clarify. When I said the car lost speed before, what I meant I meant is that the speed would set and hold, but uphill would loose the setting and slow down. This was last year and I found a leaky brake pedal switch/valve. I fixed the valve and the speed held uphill and everywhere else. This fix lasted a month or so, then went back to being leaky and loosing set speed uphill. At that point it was very cold and I decided to not worry about it until warmer weather. Then at some point the cruise control stopped engaging all together. Just would not kick in and hold speed (even temporarily). Again, I ignored the problem because we just did not need cruise control that much. However now that the warmer weather is ending I want to solve the problem.
What I have done now is the following.
1. I have repaired the pedal switch/valve to hold vacuum much better than before. Before I used some dielectric grease on the o-ring, which was very temporary. Now I cleaned everything from the inside of the switch and wrapped two layers of teflon tape on the plunger of the switch. I then tested the switch with a mity vac and it hold at least 15 psi indefinitely. I re-installed and re-adjusted the switch.
2. I unplugged the "T" connector from the pump in the engine compartment and applied enough vacuum to that connection with my mity vac to fully compress the servo's diaphragm at the throttle and hold it for a long time. It took about 10-12 psi of vacuum to fully bring the throttle cable to the limit of its travel. This proves that I have no leaks in the system. The servo is holding vacuum, the pedal switch is holding vacuum, the lines are holding vacuum.
3. I performed all the diagnostic testes I could find. Namely the B2 mode 1 and mode 2. On mode 1 I got 1-1-1 after driving over 22 mph. On mode 2 I got all the appropriate codes for all the components: brake light switch (1-3-2), resume switch (1-2-3), set switch (1-3-1), start inhibitor switch (2-2-3). I could not get the (1-1-3) code, but I assume it's because I do not have a clutch pedal switch (automatic car).
4. I have, since I posted the original post, tested the vacuum pump by applying 12V to the bottom and GND to other two terminals and hearing the pump run. I could not get the top two terminals at GND at the same time, so I could not get the vacuum to build up enough to hold the servo, but the pump runs and creates vacuum. I also heard the internal bleed-off valve click and operate as I applied GND to the top terminal. I will try to create a jig to apply GND to both middle and top terminal on the pump connector so I can see it build up the vacuum to activate the servo, but at this point I am pretty certain it will work just fine.
So, I have all these tests and results and still no cruise control. Is there a relay to activate the vacuum pump? Do I suspect the CC module next? I hear these modules almost never fail.
Thanks!
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Vladimir. '98 S70 base, 5-speed manual - his, '93 945 - hers
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Dear vladimir,
Hope you're well. I recall posts reportings that when the bulb failure relay malfunctioned, cruise control did not work. You might want to swamp a "known good" spare bulb failure relay (red-orange cylinder, central relay block [behind front center console ashtray]), row farthest from the seats.
Check Fuse #12. Through it flows power to the back-up lights (do those work?) and the cruise control system.
Hope this helps.
Yours faithfully,
Spook
p.s. This post was obstructed by a letter-based captcha. As a responsible site user, I resent - bitterly - being obstructed. Had your post not concerned a key vehicle system (cruise control), I'd not have replied to your post.
Pleease message Jarrod and ask him to stop using letter-basecd captchas: numeral-based captchas work for E-bay, which has a far greater need for effective site security.
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Well, I substituted a known good bulb out relay (the red cylinder) and still no CC. I don't have a spare module or that would be my next move...
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Vladimir. '98 S70 base, 5-speed manual - his, '93 945 - hers
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I just went through the cruise control on my auction car, a 93 940 that had problems. I found the wiring broken from the set/resume etc. switch on the steering column by doing continuity checks from the connector there to the plug to the vacuum pump. I had a spare but it was my last. I now have three switches with broken wiring so that is a common failure point. You do have to take the steering wheel off and pin the clockspring in the process but, it is surprisingly easy. But, follow the faqs on this and be sure to disconnect the battery. I have had the control module, Part. no. 9130207, fail intermittently on one car several years ago. They are tough to replace but not impossible and are located to the left of the left drivers leg on the inside fender wall. This kinda sounds like your problem only because the problem was intermittent. I have also had one vacuum pump fail.
An interesting point is when testing the cruise, I thought I would save the short drives by jacking up the rear of the differential and trying to enable the cruise but found that this would not work. After I fixed the last problem, I saw that the vacuum diaphram would start to collapse while my wife was trying the cruise but it would not stay engaged. The slop in the drive train (I think) would somehow disable the cruise control. Any explanations from folks reading this?
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Mine: 4-940s running, 2-740 and 1-940 parts cars, and 3 1959 John Deere 630s (1 for parts), dtr1:3-940s, dtr2:1-740
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Removing the steering wheel is NOT necessary. See the FAQ for the trick:
http://www.brickboard.com/FAQ/700-900/ElectricalInstruments.htm#ReplacingTurnSignalorWiperStalks
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See the 700/900 "FAQ" at the menu bar top screen left side.
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Thanks for the info. I am assuming the stalk wiring is good since I am able to get consistent diagnostic responses (B2 mode tests the resume and set buttons). If the wiring was bad there I would not be able to get the diagnostics to pass. That's my logic, anyway. Feel free to punch a hole through it. I am not proud, just looking to fix this.
The module looks like it's held by two screws. I am about to pull it out and look at it. I do not have a spare, so I am not sure what the use of this is except to look busy. I wish there was a diagnostic where you could actually engage the CC while the car is at rest. If the engine is not on, what's the harm?
If anyone has a spare CC module for this car and wants lend/sell it to me, please let me know. I think this is the only logical thing left. Everything else checks out.
Thanks, folks!
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Vladimir. '98 S70 base, 5-speed manual - his, '93 945 - hers
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Dear Vladimir,
Hope you're well. There's no need to remove the steering wheel, to change a turn signal switch. It is necessary to remove the plastic bezel, the is between the steering wheel and the dashboard. That bezel is secured by two Torx screws (T-15), if I recall correctly. Removing the instrument cluster allows access to the turn signal's connector.
I can provide step-by-step guidance on how to do this, if that helps.
Yours faithfully,
Spook
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Thanks! Do you think that I should bother with the turn signal stalk? My
diagnostics on B2 mode 2 respond to both "resume" and "set" functions
appropriately. I do not have a spare anyway, but I am thinking it is
uncalled for. Correct me if my logic is off.
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Thanks for the reply.
I do have a known good failed light relay I saved from my previous 940 (it costs around $100!). I see absolutely no symptoms of that relay being bad, but since I have a spare I will certainly try it. I did check fuse 12 and that is fine.
Sorry about the captcha. I've never seen that on BB. It just lets me post...
--
Vladimir
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Vladimir. '98 S70 base, 5-speed manual - his, '93 945 - hers
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Dear Vladimir,
Hope you're well. Thanks for the update. As to the captchas, they suddenly began to intrude, and that intrusion is intermittent. If they were numeral-based, I could easily get past them. But letter-based captchas - at least those using lower-case letters - need to go the way of the dinosaur.
Yours faithfully,
Spook
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I hear you. Capchas in general are not the greatest, but some of them are far worse than others.
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Vladimir. '98 S70 base, 5-speed manual - his, '93 945 - hers
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