Cruise Control Stopped Working - DTC P0581 - 2006 Navigator

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AGrayson84

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Hi everyone, I've read up on several threads on this forum and across the internet about this issue, and can't seem to be able to pinpoint my problem. Almost 3 months ago I removed all of the bolts on my dash pulled it away from the firewall, as far as I could without disconnecting the steering column (I did drop the column from the dash, just didn't disconnect it from the steering shaft). I pulled my A/C plenum and replaced everything in/on it, and re-installed everything.

Either immediately after this, or after I replaced a both front brake lines and my master cylinder a week later, I lost my cruise control. It definitely worked before all of this. I see code P0581 (Cruise Control Multifunction Circuit High) when I check my DTC's, but this code is not illuminating the check engine light.

I've checked the fuses, done some of the procedures in my PC/ED CD, tried the self test, among other things, but no dice yet. All stereo and speed control buttons on the steering wheel light up at night time, and the stereo buttons work perfectly and so does the horn. But pressing the ON and SET + buttons on the car while driving over 30 MPH does nothing at all anymore.

When I attempt the self test, I have tried it with the parking brake engaged as well as disengaged, and I get no cruise control light on the instrument cluster after turning the ignition key on while holding the "OFF" button. Does this indicate a problem??????? In fact, without holding the OFF button, I simply get no speed control light on the dash at all when all the other instrument cluster lights (except high beam) come on for the couple of seconds after cycling the ignition key to the ON position. Not sure if the speed control light should light with the rest of the lights or not when turning the ignition on, but mine is definitely not lighting. I though maybe there was a bad bulb, but after removing the instrument cluster I found that there are no generic, incandescent bulbs you can twist out like on other vehicles.

I've checked the connections for the clock spring to ensure they are fully seated and there are no loose pins. I then removed the air bag and removed the steering wheel controls to clean them as I've read about doing, but there are no contacts on my to corrode nor clean. Just a couple of circuit boards with small buttons and LED's. And they look like they are brand new... no dirt, corrosion, rust, etc.

I check that the plunger to the left of the parking brake, for the cruise control, seems to be operating fine. I'll have to check to see if the circuit is opening and closing as it should later this week. I've also checked to make sure the secondary cruise control switch on the master cylinder (it was a Motorcraft unit, with brand new switch too) is connected and no loose wires.

I tried following the PC/ED troubleshooting guide, but after getting a bit of the way through troubleshooting for P0581 I found that guide to be very misleading. It starts with telling you to check circuit 151 (light blue / black) as well as 848 (dark green / orange) for voltage, and if both have voltage proceed to step C2, but if both don't have voltage then proceed to C4. Well, I later found that circuit 848 is ground, so it clearly shouldn't have voltage, so going to step C4 was not the right answer. Step C2 asks if any voltage is present. There is voltage present in circuit 151 (5 volts), and I later found that there is supposed to be voltage on this circuit with the key on, so the suggested short to voltage on this circuit, per the PC/ED, isn't accurate.

I have a digital multi-meter, and I also have FORScan on my phone as well as my Windows laptop. I'm not seeing anything I can do to try to read input from the cruise control switch, nor manually trigger the cruise control using the Input Control options on my laptop.... there doesn't seem to be an input control option for this. Does anyone have any ideas as to what I might be able to try to do next? I have some long road trips coming up next month and hoping to get this sorted out before then. I do have some piercing probes for my multimeter so I may have to start checking for a short between the steering wheel switch wiring and the wires going into the back side of the clock spring to see if there is a short in the clock spring. I can also back-probe the connectors on both ends of the clock spring and check for continuity that way. Is there anything I should expect to see voltage-wise on the light blue/black wire, or resistance-wise on the dark green/orange wire when pressing the ON button for the cruise control? What about the SET + button?? Any other ways to test the cruise control buttons for function? Any connector besides at the steering column (ie: behind/under the dash on the passenger side) that I may have left undone when re-installing the dash???? Thanks everyone!!!!!!!!

-Andrew
 

Allen Miller

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A few things that were helpful to me:
  • The switches all lit up at night - the backlight is a separate circuit to any of the inputs. So the backlight working should not be taken as a sign that your switches are good.
  • The CC light on the dash doesn't light up with the rest of the bulb checks at startup on my 02 explorer or the 03 EB expy that I was diagnosing, so I would take that as normal operation.
  • The CC switch self test: hold off while turning on, but not starting (this doesn't flash the CC light); ON (flash); RESUME (flash); COAST (flash); CANCEL (flash)
    • If any switch fails it will cancel the rest of the self-test.
  • There are three leads going to the EB switches - I"m not sure what it looks like on the Navi, but the top two were the signal circuits - each switch sends a different resistance across these two terminals.
    • Based on my experience testing these in the junkyard, the ON switch is a common failure on the EB switches - I'd assume the Navi switch set is similarly wired and similarly prone to a failure of the ON switch.
  • https://www.autocodes.com/p0581.html This site lists a failed cruise control multifunction switch as a probable cause for the code listed.
Based on all that, I'd suggest that you get a switch out of a junkyard since they are like $200 new, and usually under $10 at the junkyard - Just test it before you buy it. I tested 4 switches in the junkyard and only 1 was good.
 

Bedrck47

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There is a way to test the switches at the PCM connector Read Test A


PINPOINT TEST A: THE SPEED CONTROL IS INOPERATIVE
Test Step
Result / Action to Take
A1 RETRIEVE THE RECORDED PCM DTCs FROM BOTH THE CONTINUOUS AND ON-DEMAND SELF-TESTS
  • Check for recorded PCM DTCs from the continuous and on-demand self-tests.
  • Are any DTCs recorded?
Yes
REFER to the Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index.

No
GO to A2 .
A2 CHECK THE SPEED CONTROL SWITCH
  • Key in OFF position.
  • Disconnect: PCM C175b.
  • Measure the resistance between the PCM C175b-56, circuit 151 (LB/BK), harness side and the PCM C175b-57, circuit 848 (DG/OG), harness side while pressing the speed control buttons as follows:

    Speed Control Switch Resistance Value
    OFF Less than 5 ohms
    SET - 285 - 315 ohms
    SET + 570 - 630 ohms
    RESUME 1,055 - 1,165 ohms
    ON 2,004 - 2,216 ohms
    No switch pressed 4,094 - 4,526 ohms


    S6J~tr~en~file=N0002245.gif~gen~ref.gif
  • Are the speed control switch resistance values OK?
Yes
GO to A3 .

No
Go To Pinpoint Test C .
A3 CHECK THE DIGITAL TR SENSOR
  • Connect: PCM C175b.
  • Apply the parking brake.
  • Key in ON position.
  • Enter the following diagnostic mode on the diagnostic tool: PCM Digital TR Sensor PID.
  • Monitor the digital TR sensor PID.
  • Select DRIVE.
  • Does the PID value agree with the transmission range selector lever position?
Yes
GO to A4 .

No
REFER to Section 307-01A or Section 307-01B to continue diagnosis of the digital TR sensor.
 
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AGrayson84

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Read the attached link. Similar problem. Let me know if you want to troubleshoot this

http://www.expeditionforum.com/threads/2003-cruise-control-issue.9112/


Thanks Bedrck, I had actually read through that thread and followed it that past few days to see if it ended up being of any help to me. Unfortunately it seems as though the Expedition has different switched all-together, including the internal circuit board and all. Also the fact that my instrument cluster doesn't have replaceable bulbs comes into play-- I think the few difference between the models make following Allen's troubleshooting in his thread a little irrelevant (not totally irrelevant, just certain aspects of it). :)



A few things that were helpful to me:
  • The switches all lit up at night - the backlight is a separate circuit to any of the inputs. So the backlight working should not be taken as a sign that your switches are good.
  • The CC light on the dash doesn't light up with the rest of the bulb checks at startup on my 02 explorer or the 03 EB expy that I was diagnosing, so I would take that as normal operation.
  • The CC switch self test: hold off while turning on, but not starting (this doesn't flash the CC light); ON (flash); RESUME (flash); COAST (flash); CANCEL (flash)
    • If any switch fails it will cancel the rest of the self-test.
  • There are three leads going to the EB switches - I"m not sure what it looks like on the Navi, but the top two were the signal circuits - each switch sends a different resistance across these two terminals.
    • Based on my experience testing these in the junkyard, the ON switch is a common failure on the EB switches - I'd assume the Navi switch set is similarly wired and similarly prone to a failure of the ON switch.
  • https://www.autocodes.com/p0581.html This site lists a failed cruise control multifunction switch as a probable cause for the code listed.
Based on all that, I'd suggest that you get a switch out of a junkyard since they are like $200 new, and usually under $10 at the junkyard - Just test it before you buy it. I tested 4 switches in the junkyard and only 1 was good.

Thank you Allen, good to know that the speed control light not coming on during startup is expected. I definitely understand that the backlighting for the switches is a different circuit, was just mentioning the horn, backlighting, and stereo control still working to possibly eliminate the clockspring from the equation.

Good point about not necessarily seeing any lights when simply holding the OFF button, but once I turned the key to ON, released the OFF button, and tapped the ON button (all within 5 seconds) I still do not see the speed control light illuminate on the instrument cluster.

So on my Navigator I actually have 4 leads going to the circuit board for the cruise control.

Here is a set I grabbed out of another Navigator this-past Saturday, so you can see what I'm working with:

eap3wp.jpg

2dmegzc.jpg

^Those came out of a Navigator without the touch-screen, navigation head unit. In place of the "Voice" switch on the bottom of the cruise control switch, like on my Ultimate model, this one had a "Media" switch on the bottom, I suppose to change audio source on the stereo. These circuit boards are also tan in color, whereas my originals are red in color. I figured they would still work, but after plugging them in, only some of the buttons lit up, and the stereo controls on the opposite side of the airbag where not longer doing the functions that the buttons are labeled for (ie: volume down did nothing, next track turned the volume down, etc.). Cruise control still didn't work over 30 MPH, so I swapped my original controls back in and everything is fine again. Finding an Ultimate edition of an '05/'06 Navigator in a junk yard around here has been impossible, so I might just have to order a new set and hope it fixes the problem, if more troubleshooting this weekend doesn't narrow down my problem.
 
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OP
A

AGrayson84

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There is a way to test the switches at the PCM connector Read Test A


PINPOINT TEST A: THE SPEED CONTROL IS INOPERATIVE
Test Step
Result / Action to Take
A1 RETRIEVE THE RECORDED PCM DTCs FROM BOTH THE CONTINUOUS AND ON-DEMAND SELF-TESTS
  • Check for recorded PCM DTCs from the continuous and on-demand self-tests.
  • Are any DTCs recorded?
Yes
REFER to the Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index.

No
GO to A2 .
A2 CHECK THE SPEED CONTROL SWITCH
  • Key in OFF position.
  • Disconnect: PCM C175b.
  • Measure the resistance between the PCM C175b-56, circuit 151 (LB/BK), harness side and the PCM C175b-57, circuit 848 (DG/OG), harness side while pressing the speed control buttons as follows:

    Speed Control Switch Resistance Value
    OFF Less than 5 ohms
    SET - 285 - 315 ohms
    SET + 570 - 630 ohms
    RESUME 1,055 - 1,165 ohms
    ON 2,004 - 2,216 ohms
    No switch pressed 4,094 - 4,526 ohms


    S6J~tr~en~file=N0002245.gif~gen~ref.gif
  • Are the speed control switch resistance values OK?
Yes
GO to A3 .

No
Go To Pinpoint Test C .
A3 CHECK THE DIGITAL TR SENSOR
  • Connect: PCM C175b.
  • Apply the parking brake.
  • Key in ON position.
  • Enter the following diagnostic mode on the diagnostic tool: PCM Digital TR Sensor PID.
  • Monitor the digital TR sensor PID.
  • Select DRIVE.
  • Does the PID value agree with the transmission range selector lever position?
Yes
GO to A4 .

No
REFER to Section 307-01A or Section 307-01B to continue diagnosis of the digital TR sensor.

Thanks again Bedrck! Looks like you're looking at the same workshop manual as me (Section 310-03 for the '06 Navigator/Expedition). I honestly skipped right over Pinpoint Test A since I have code P0581, which points straight to Test C, but I will gladly still run through Test A this weekend..... I have the rest of the test and looks like it will be useful to do, no doubt.




Thanks once again for the help so far guys! I appreciate it greatly, and will report back findings of my additional troubleshooting this weekend. :)
 

Allen Miller

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Good point about not necessarily seeing any lights when simply holding the OFF button, but once I turned the key to ON, released the OFF button, and tapped the ON button (all within 5 seconds) I still do not see the speed control light illuminate on the instrument cluster.
Well, I'd say that your "on" switch has probably failed. Look forward to hearing what you see after popping a new switch in there.

I will add a caveat: when I was doing my troubleshooting, the window seemed like it was a lot closer to 2 seconds than 5 seconds between turning the ignition on and pressing the on button on the cruise control.
 
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OP
A

AGrayson84

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Thanks for the response again Allen. I've weary to think the ON switch has failed, due to the fact that it's a totally different design that the Expedition switches that seem to fail, but I still have not rule that out. I did also try turning the key on, and then within 2 seconds releasing the off button and tapping the ON button, but still no speed control light on the IC. Thanks for that tip though!!

I tried checking the resistance values on the switch, and followed Pinpoint Test A. I get no resistance between the two circuits regardless of whether a button is pressed or not. However, after removing the air bag again and disconnecting the steering wheel switches from the clock spring, I checked the resistance values directly from the switch connector (the one that plugs into the clock spring, behind the air bag, when the airbag is normally installed). Checking the values there, disconnected from everything else, everything is perfect-- the values for nothing pressed, as well as the values for each button...... everything is perfectly within the range mentioned in test A. But I'm really not sure if that means the switches are good, with 100% certainty or not. Does that rule out the possibility of voltage from another circuit on the switch's circuit board possibly bleeding across another circuit(s)??? Because Pinpoint Test A seems to only be for cruise control that is not operational, but also NOT throwing a DTC. It tells you to go to test C (the one I've already done mostly) if the resistances aren't within spec while checking from the disconnected PCM harness (C175b) with the key on and the parking lights on.

I found another of the same model clock spring in a junk yard and swapped it in, just to see if it helped, and same results there.... I continue to see 5.xx volts on circuit 848 (which is supposed to be a ground). I then found that with PCM connector C175b disconnected (but everything else connected), circuit 848 on the steering wheel control wiring is getting 5 volts or of power. This circuit is grounded to the same metal that the airbag is secure to.... it's definitely meant to be a grounded circuit, but it is getting voltage somewhere--whether it be a short within the switch circuitry board, or somewhere else between the switch and the PCM. The separate contact plate on the back of the airbag, that is used for the horn, has continuity between that plate and the rest of the airbag that it secures to (it's not supposed to, as far as I knows), so it appears that MIGHT be where circuit 848 is getting some of it's power?? The wire to the horn, which attaches to the contact plate, has 12 volts with the key on. If I disconnect that wire from the contact plate, I no longer have continuity between the contact plate and the rest of the airbag assembly, and therefore no longer getting voltage to circuit 848 when I check it at it's ground terminal on the airbag assembly. Yet, somehow, that same circuit (848) at disconnected PCM harness C175b continues to show 5.xx volts there. That makes no sense, since the circuit should be complete from the steering wheel switches to the disconnected PCM harness. I guess I need to check continuity from the steering wheel controls to C175b and see what I have... because it almost sounds like that circuit get swapped somewhere down the line, when I can guarantee you none of the wire has been touched. But it just doesn't make sense that one end of the circuit shows no voltage, and the other end does, while everything is connected. I guess I also should check circuit 848 at the steering wheel for continuity to ground, with and without C175b connected.

Also, during my testing of circuits 151 and 848 in pinpoint test C4, check for short to ground, 151 has no continuity to ground, but 848 has 4.56 kilo ohms. The workshop manual doesn't tell you if 848 is supposed to have voltage or ground, and doesn't tell you if 151 is supposed to have voltage or ground. The scenario is if there is voltage on either wire, go the next step, or if there is ground on either wire go to the next step.... which seems very odd to me. But anyhow, 848 is getting voltage, AND it has continuity to ground apparently. I checked the wiring several inches back from each connector and those two circuits look fine everywhere I've looked so far. I feel it's unlikely that 848 is picking up power against another circuit somewhere in the wiring harness between the PCM and the switches (I did check the actual switch harness itself for chaffed wiring, shorts, etc. and all looked good there).

Another thing that is odd is that I continue to get code P0581 after completely unplugging the clock spring and the steering wheel controls from the circuit, and after I clear the code. I'm not sure if that's telling me there's still a voltage issue, and the issue is NOT the clock spring nor steering wheel controls, or if that code just won't go away until the issue is resolved. I can't imagine the latter being the scenario for this code, and with the clock spring and steering wheel controls disconnected from the circuit, I see no power to circuit 848 at the PCM harness C175b anymore. So to me, NOTHING is making any sense here. No result is correlating with logic like it should.

I ordered a new steering wheel control set last week so hopefully it'll be here soon and I can plug it in and see what happens... but this just isn't making a lot of sense to me. One test points to the clock spring or the steering controls being the issue, but when unplugging both from the circuit I still get P0581, like it's still recognizing voltage where it shouldn't be, or voltage being higher than it should be on a circuit that is meant to have voltage. Without knowing what voltage any of the circuits should have at any given scenario this is becoming difficult to troubleshoot. And since circuit 151 shows no voltage during test C1, but 848 shows 5 volts, yet 151 is supposed to be the power and 848 is supposed to be the ground.... I'm not sure what to even make of that.

Lol I'm hitting a brick wall here, and now going to end up probably replacing a bunch of parts and doing a bunch more troubleshooting before this gets sorted out. Aggravating as hell, especially since I've sunk $1,500 in an entirely new A/C system recently and still can't get it to perform properly. This truck is kicking my butt lol
 

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