Quadzilla iQuad - no mph

[Chris O.]

Oh I just re-read the tread, I thought you guys are talking about map sensor.

Beer probably isn’t helping here either

[SavageTusk]

Well ecu back and a lot running well with the new software, oil pressure is working now.  However, I can't figure out why the Quadzilla won't read mph.  Still 0.  Speedo works on the Instrument cluster but nothing on the Quadzilla.  I guess I'll try a new map sensor?  Truck runs great, just no mph 

Edited October 5, 2018 by SavageTusk

[SavageTusk]

On 9/23/2018 at 10:02 PM, Me78569 said:

Iquad used the ecm reported speed so if you have no mph then the issue is likely in the wiring.

So 45 on the ecm ends up going to the pcm (grey/black). What I don't understand is why the speedometer works and the quadzilla does not receive a signal.  What harness on the quadzilla reads the speed?

[Mopar1973Man]

That is tachometer signal not road speed. Road speed is reported over the CCD network from the ABS to ECM. Another way to tell also is if the ECM do not receive speed info from CCD the grid heater will continue to cycle after 20 MPH.

[Me78569]

Yep, the cluster is getting speed via the CCD bus, the ecm may or may not get that message for any number of reasons.

[Mopar1973Man]

Most all data is sent over the CCD network as for the speed signal its used but both PCM and ECM both. 

[SavageTusk]

I don't know what to think.  I replaced the oil pressure sensor and it was working fine, matching the mechanical gauge.  To address the no mph showing on the quadzilla, I replaced the speed sensor on the rear axle and still nothing.  

 

Here's the really strange thing.  I replaced the MAP sensor and now the oil pressure sensor is going bonkers again.  Yes I know the locations of the MAP and Oil pressure sensors.  I just don't get it.  I had the codes cleared a while back so maybe I'll get them read again.  I just don't know..

[Dieselfuture]

4 hours ago, SavageTusk said:

I just don't know..

You got one of the hunted ones just like I do, the more you fix it and baby it the more it gives you problems. I'm going to ignore mine for a while see what it thinks of that.

[SavageTusk]

Drove fine to work yesterday.  It rained all day, went out to the truck after work and turned the key and I think every light came on blinking here and there.  In the odometer it read "no bus"  It started right up and then just shut down..all power.  Batteries were fine, I could crank the engine but nothing when you turn the key;  just a flicker of the wait to start light and then nothing.  I checked about as many fuses as I could in the rain, eventually having it towed to the dealership.    Always sad to see your truck on a flatbed.  And now I wait, I wonder what the issue will be...besides the bill. 

Edited October 26, 2018 by SavageTusk

[Dieselfuture]

That suks. Definitely something electrical, but what... just need to start eliminating one thing at a time 

Have you checked your alternator for AC noise yet?

[SavageTusk]

Well reviewing the wiring diagrams this morning got me thinking.  There was no power at all to the vehicle besides the starter.

 

I decided to go out to the dealership which hadn't started working on my truck yet and with a can of electrical cleaner spray and dielectric grease pulled the main power plug, cleaned, spread dielectric grease over the connections and screwed it back to the main fuse panel under the hood.  I'll be damned it worked, and the oil pressure gauge worked.  I was able to drive home.  I still have no MPH on the Quadzilla and nervous about water messing something up again, but progress!  I have a check engine light on so I'll get the code(s) read tomorrow.  I have a feeling I need to go through the wiring.  Any suggestions on where to start?

[SavageTusk]

On 10/10/2018 at 10:49 AM, Mopar1973Man said:

Most all data is sent over the CCD network as for the speed signal its used but both PCM and ECM both. 

@Mopar1973Man are you saying to run a jumper from the white/BLK from the ABS to the white/BLK at the ECM? I was reading this article and seemed to work for this guy, little different scenario.  

 

Edited October 29, 2018 by SavageTusk

[Mopar1973Man]

44 minutes ago, SavageTusk said:

@Mopar1973Man are you saying to run a jumper from the white/BLK from the ABS to the white/BLK at the ECM?

 

No. What I'm saying is to inspect your current wiring. The speed signal is already used by the ECM to cancel the grid heaters.

[SavageTusk]

3 minutes ago, Mopar1973Man said:

 

No. What I'm saying is to inspect your current wiring. The speed signal is already used by the ECM to cancel the grid heaters.

Interesting you mentioned that.  One of my grid heter terminal boots is melted a bit.  I've never seen it hot but was like that when I got the truck.  If I'm receiving vss to the speedo via pin 6 on the joint connector that goes to the speedo (CCD+) it must be an open between there and the abs module pin 12  or from the abs module to pin 27 on the PCM.

[Mopar1973Man]

The speed data is digital. So both wires are required. Then if the CCD network is down to any device then the ECM or PCM would toss either P1694 or P1698 codes. So if there are neither codes then the network is functional. 

 

If the ECM has no CCD signal...

 

If the PCM has no signal...

 

[SavageTusk]

Thank you, it seems like I may have an issue with my PCM. I got this code yesterday at oriellys. I'm down from 11 codes to 3 though.  There's hope! 1689 & 0237 were the other two.

Edited October 29, 2018 by SavageTusk

[Dieselfuture]

Who rebuilt your ECM, I had similar experience with https://autocomputerspecialist.com

I purchased a used ECM locally and send it to them to program it to my truck so I have a spare, don't ask me why. When I got it back and plugged it in I had a bunch of codes right off the bat. I cleared all the codes and none were present for few days, then out of blue I lost my tachometer,  check engine light came on. Drove it home, seem to run fine other than no tach, scan for codes and had 1698. I knew there was nothing wrong with my PCM so I swapped ECM to my original one and all problems went away. That's why I think the problem might be in your ECM. I suppose it could be wiring related and maybe I got lucky by switching ecms out problem when a way, but I really think there is an internal hardware issue with ECM. I called Auto Computer Specialists back and they told me that I need to send ECM back so they can fix it and that programming I had them do and fixing it was two separate issues. I asked them if they need to reprogram it again and they said no just need to fix something internally on ECM board. Which of course I never put that ECM in my truck before I send it out so I don't know if that problem was present before or not. Also I had them enable my high idle/3cyl which they called, cold idle.

Be interesting to find out what your problem is.

[SavageTusk]

3 hours ago, Dieselfuture said:

I had them enable my high idle/3cyl which they called, cold idle.

Be interesting to find out what your problem is.

 

I never had it rebuilt just reflashed to 2001 stock by Bob at Smarty.  I honestly don't know if it's my PCM, ECM or wiring.  Something is off and the 1698 code leads to the PCM.  I'm working with https://carcomputerexchange.com/ right now, since they have a money back guarantee, I fugure it can't hurt anything to get both the PCM and ECM both,  then try one at a time, then I can send back what I don't need.  Good thinking on the idle/3cyl for the ECM.

Edited October 29, 2018 by SavageTusk

[Mopar1973Man]

You need to read this article and do the testing. It could be any module causing the issue of communication. Basically if the CCD network is shorted to ground, +5V or +12V that network is dead. You need to measure the CCD voltages which should be 2.49 and 2.51 volts out of the OBDII port. Then if they are not, keep disconnecting modules till it returns. The module you disconnect and the bias voltage returns then that is the module that failed. PCM supplies the network its required. I'm pretty sure the Cluster is what supplies the bias voltage. @Chris O. I think can verify this.

[SavageTusk]

1 hour ago, Mopar1973Man said:

You need to read this article and do the testing. It could be any module causing the issue of communication. Basically if the CCD network is shorted to ground, +5V or +12V that network is dead. You need to measure the CCD voltages which should be 2.49 and 2.51 volts out of the OBDII port. Then if they are not, keep disconnecting modules till it returns. The module you disconnect and the bias voltage returns then that is the module that failed. PCM supplies the network its required. I'm pretty sure the Cluster is what supplies the bias voltage. @Chris O. I think can verify this.

 

That is VERY Informative, I think I'm starting to get it now, I know, I know, sometimes it takes a while, lol.  

 

So

pin 3 on the OBD2 plug (violet/brown this is the ccd bus+) should be 2.49v

pin 11 on the OBD2 plug (white/black this is ccd bus-) should be 2.51v

 

When I am measuring the voltages, I can disconnect the modules, one at a time until the voltages return to those values.

 

Testing:

PCM - leave hooked up (source of network)

 

Unplug:

CTM - left side of dash

Radio

Instrument Cluster

Air bag control module - Lower center of dash

ABS - on hydro under hood

Overhead console - Deleted in my truck, already disconnected

ECM

Edited October 29, 2018 by SavageTusk
Updated per mopar man's comment