Check Engine Light On 84 10 Road Speed error

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Check Engine Light On 84 10 Road Speed error

May 13, 2021, 01:41:47 pm

Hi folks, I seem to have developed a solid error code causing the Check Engine light to remain on, (plus that great hypnotic dinging...).

While traveling North on I-95 in South Carolina last week over some rough stretch of road this problem occurred.

Silver leaf is showing ENG-SPN 84 10 road speed abnormal change, plus ENG-SPN 0 0 unknown component high reading... The Allison transmission pad has no error codes

? Which I thought was odd.

The coach drives without any problems, speedo works, cruise control works, shifting is normal. So, we drove it another 900 miles to our kids home in Connecticut.

Reading the forum, this problem seems to be pointing to the Allison speed sensor on the tail shaft... I checked at the transmission, pulled connector, cleaned the connector, re-seated. Everything looks OK. Did the same for the other sensor on the transmission. I did not remove the sensor, or check ohms.

I reset the Silverleaf codes, started the engine and immediately got Check Engine light, etc... Silver leaf still reporting the 84 10 codes, this is without moving the Coach.

I called the local Allison Dealer here, they have the sensor.

Here's my dilemma: I talked to the Service Manager at Allison, he took me through some diagnostic questions. His point is, he believes the Allison Transmission should show an error code if this sensor is in fact really broke.. Since it's not registering a fault code, he is suggesting that this is a Cummins ECU problem, (or cable). So, his recommendation is not replace the sensor, bring the coach to Cummins.

Any thoughts on this issue from the experts here? I am puzzled...

Update: Forgot about the fact that while clearing the Silverleaf error codes, this does not clear the Cummins engine ECU codes. So, I'm going to do the engine ignition on/off sequence 10 -15 times. I suspect that will clear the ECU code. Ithink this is an intermittent problem caused by rough roads... Recommendation I got yesterday from a member was to clean the ECU cable connectors at the engine block, add some dielectric grease to those contacts. Also check the termination resisters that are close to that ECU cable connector, could cause issues if cracked due to heat, vibration.

Thanks in advance, Jeff

Re: Check Engine Light On 84 10 Road Speed error

Reply #1 – May 17, 2021, 08:45:02 am

Error was reset using the on/off cycling of the ignition key. So, it's an intermittent issue likely caused by road conditions. Cleaned the connector and applied di-electric grease.

Talked to another member who has the same problem, 2002 FT. His is at a Cummins Dealer in the shop for maintenance and a look at the same problem. He said the Cummins Manager indicated that this error code is a constant complaint among MH owners. That line of code was added to the CUMMINS ECM to alert owners of fleet trucks to perhaps, poor driving technique... Wheel slip. He asked if they could delete that line of code in the ECM. Will know in a couple days if they took that action. Interesting.

Best, Jeff

Re: Check Engine Light On 84 10 Road Speed error

Reply #2 – May 17, 2021, 11:29:05 am

I've had that problem also, agrivating. Seems to happen most often after driving on loose surfaces and making turns. Very sporadic and I can't make it happen on demand. I found, if it does throw that code, shutting the engine down then turn the ignition on and wait a minute before starting will clear it, or three successful restarts works sometimes. I'd happily pay Cummins to disable that "feature" but they weren't helpful when I took the coach to Cummins shop so I just live with it.

Re: Check Engine Light On 84 10 Road Speed error

Reply #3 – May 17, 2021, 06:10:05 pm

Aggravating. yes!

Think I'll install a dash switch for the "dinger"...

Best, Jeff

Re: Check Engine Light On 84 10 Road Speed error

Reply #4 – May 17, 2021, 08:13:11 pm

Quote from: Beeman – May 17, 2021, 06:10:05 pm

Aggravating. yes!

Think I'll install a dash switch for the "dinger"...

The de-dinger was one of Steve's oft-used modifications

Re: Check Engine Light On 84 10 Road Speed error

Reply #5 – June 20, 2021, 11:40:13 pm

I ran into the same issue today. Two questions...

How many key cycles clears the dash light/dinger?

What's the de-dinger consist of? I need one.

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Re: Check Engine Light On 84 10 Road Speed error

Reply #6 – June 21, 2021, 08:21:07 am

Find the annunciator (the thing that dings) and add a switch in either wire to it find an out of the way place for the switch. Later years may have has the dinging thing on a circuit board. Harder to do. If you switch off the dinger you will also disble the turn signal beeping. There is a work around for that, diodes required. And you cn make it ding if the headlights get left on with the ignition off, a relay and maybe a diode or two for that.

Turn Signal Beeper Work-around When Annunciator is Disconnected.

Re: Check Engine Light On 84 10 Road Speed error

Reply #7 – June 21, 2021, 09:33:52 am

I disconnected my dinger. Is that dangerous? I keep a pretty good watch over the VCMpc and dash. Am I kidding myself?

Re: Check Engine Light On 84 10 Road Speed error

Reply #8 – June 21, 2021, 09:42:01 am

Quote from: Michaelhayley – June 21, 2021, 09:33:52 am

I disconnected my dinger. Is that dangerous? I keep a pretty good watch over the VCMpc and dash. Am I kidding myself?

Dot requires that there is a audible alert for low air pressure. Guess if you were deaf it wouldn't help much?
Scott

Re: Check Engine Light On 84 10 Road Speed error

Reply #9 – June 21, 2021, 12:17:08 pm

On the 2001 coaches with the gray box (maybe some have a blue box) the box sends a 5 volt signal to the pressure transducer at the tank, The voltage is changed by the resistance in the transducer as tank pressure changes. Some circuitry in the box interprets the resulting voltage and sends a signal to the electronic pressure gauges in the dash. When your gray box fails (and it will) there is no fixing it and no replacement for it. The work around it to install direct read mechanical gauges with an air line that goes down to a fitting on the tank. These are actually much nicer, you can see what your pressure is even if the ignition is off and the lighting is far better than in the OEM gauges.

My 12v electronic gauge connected to the gray box has also quit working. It was replaced with a direct read air pressure gauge connected to the HWH tank. I have two other ways to read start battery voltage, mainly on VMSpc.

So my annunciator has been dinging for at least 8 years because of this internal electronic failure. I installed a switch two days after the pressure gauges failed. One could disconnect the wire feeding the annunciator the come from the low pressure signal in the gray box. You could also put in low pressure switches in the air lines from the tanks that would send a signal to the annunciator if there was a low pressure event to be perfectly compliant.

Re: Check Engine Light On 84 10 Road Speed error

Reply #10 – June 21, 2021, 08:15:14 pm

I have had the same issue/error code. First time heading to MOT. I drove 10 hours the second day with the dang beep going off. (turned up the Sirius radio to drown out the beep) When I arrived MOT tightened the battery cables and said that fixed the problem.

Since I purchased the coach the ABS light has been on. Immediately after purchase MOT said that the sensors get dirty all the time and not much can be done about this.

A week and a half ago on day two of a 2,500 mile trip I hit a bump and the check engine light/audible alert went off. The Silver Leaf again reported the 84-10 vehicle speed rate of change code. Having been through this before we continued the last 30 miles to Twin Falls ID. The next morning I contact a truck (Allison & Cummins) shop. Thankfully they were able to diagnose the issue. No faults in the engine ECU or transmission. They found the issue was in the ABS wheel speed sensor. They replaced the sensor and replace the drive axel seals as they believed that the axel seal leak was causing the sensor to lose signal intermittently.

Cost me 2 coach bucks, but no problem for the remainder of the trip. The shop was Rush Truck Centers who came through for us.

I am quite concerned about having MOT do anything other than routine service (oil/filter/lube) or interior projects. MOT did my refrigerator replacement and I was happy with that. Their advice on the ABS and 84-10 fault code was suspect to say the least.

Re: Check Engine Light On 84 10 Road Speed error

Reply #11 – June 21, 2021, 11:00:27 pm

I had that issue and I had Cummins disable it. It is for fleets to see if a driver is speeding.

Re: Check Engine Light On 84 10 Road Speed error

Reply #12 – June 22, 2021, 11:18:35 am

Quote from: John S – June 21, 2021, 11:00:27 pm

I had that issue and I had Cummins disable it. It is for fleets to see if a driver is speeding.

Sure would be nice to have a list of too do's for future ECM programming to delete what we don't need or want. When I replaced my ECM I was basically just happy to have it. Still think about purchasing a Cummins Chinese new ECM zero time. My rebuilt ECM from GoECM has worked without issues but in the back of my mind I still know it has 850k miles on it since new. Rebuilt equals reprogramming. They are not physically rebuilding. I'm curious if the Mexico Cummins rebuilt units are actually rebuilt? I would assume they are but don't know. Also I'm probably overthinking it, But?
Scott

Re: Check Engine Light On 84 10 Road Speed error

Reply #13 – June 22, 2021, 11:32:03 am

The problem may not be with the ECM but can start with the injectors, ECU to injector wiring and even the fuel solenoid. The N14 is an outstanding engine but the change from mechanical to electronic was not without problems. As you can see, this applies to the other electronic Cummins engines also. Here is a partial quote:

For all of the great aspects of the Cummins N14 its Achilles Heel has always been the injectors. The L10, M11 and N14 all have problems with injector failures and the surrounding electronics. The fuel system's main components consists of the injectors, injector wiring harness and the ECM. A common occurrence will happen when, for example, when the ECM shows a 111 or 343 code in an N-14 Celect Plus model. This means the ECM isn't grounded to the injector. Usually this starts out with only 1 injector shown to be malfunctioning but can quickly spread to others. If this happens you immediately want to shut down the engine.

These early electronic engines offered no protection against the wiring harness shortening out. There are 6 injector driver connections on the ECM which are attached to the injectors via a wiring harness. If an injector goes bad it is advised to pull out the wiring from the injector and replace immediately before the faulty wire burns up the ECM motherboard. Usually if you unplug # 1, 2, 3, or 4 injector drivers in time you can save the ECM/injectors. The wiring harnesses are known to have problems and are very expensive to replace.

Another issue with the N14 ECM is a faulty fuel solenoid. The solenoid is situated on the bottom of the ECM. If the solenoid shorts it will heat up the ECM slowly and can then destroy the entire fuel solenoid circuit, memory chip and the injector timing chip. Usually the solenoid gets so hot it melts the solder on the chips. For a 50 pin connection all it takes is one pin to loosen from the heat to destroy the ECM. It is recommended that drivers carry 1-2 extra injectors in the truck in case one goes out. Usually they go out in pairs which makes sense to carry 2 at all times.

Pierce

Re: Check Engine Light On 84 10 Road Speed error

Reply #14 – July 16, 2021, 04:47:40 pm

On a trip we made a few weeks ago, we had this same code come up. It has since gone away after being cleared with VMSpc, but last weekend I noticed something else. I originally had the VMSpc plugged into the round 9-pin port, but have switched to the rectangular 12-pin port. There were a few data channels that could not be seen with the 9-pin that are now active with the 12-pin...specifically trans gear selected and attained, and retarder temp.

This makes me think the 12-pin is getting more transmission data than the 9-pin had access to. That said, on the last outing I noticed that the speed signal of the VMSpc was no longer smooth and steady, but would jump around 2-3mph constantly. With cruise set at 70, it would flicker from 67-70mph, but the cruise held stead (assumingly from the other speed sensor that the 9-pin was reporting from. That makes me think the speed sensor that the 12-pin is using may be a different one, possibly from the transmission, which goes along with what has been said above about the Allison transmission speed sensor.

If that's the case, it looks like I've got an issue with that sensor. Out of caution, I'd like to replace it. Does anyone have the part number for it for the 4000MHR trans?

Re: Check Engine Light On 84 10 Road Speed error

Reply #15 – July 16, 2021, 06:08:07 pm

Quote from: WS6_Keith – July 16, 2021, 04:47:40 pm

If that's the case, it looks like I've got an issue with that sensor. Out of caution, I'd like to replace it. Does anyone have the part number for it for the 4000MHR trans?

We got our replacement output speed sensor from a Freightliner dealer. Just take your transmission data plate info - they will need the model and serial number of the transmission to make sure you get the right sensor. If output I know the one for transmission with retarder is different than for one without.

Re: Check Engine Light On 84 10 Road Speed error

Reply #16 – July 16, 2021, 06:16:58 pm

Ah - found a PM conversation I had with Mike Rash about this. At the time (2014) I sent him

Quote

We have the HD4000MHR, according to the data plate on the transmission. The photo of the package for the new part says p/n 29544139

The Freightliner dealer mentioned this was an updated version - from what we can tell, the "update" is that it's now a right angle and not a straight plug. Makes it more obvious which is the output speed sensor when installed.

And lookie here - I found a photo I snapped of the package

Re: Check Engine Light On 84 10 Road Speed error

Reply #17 – July 19, 2021, 04:40:45 pm

To followup, I did find the SN tag, called W.W.Williams and this is the same part number that gave me for the output speed sensor. $125.

Re: Check Engine Light On 84 10 Road Speed error

Reply #18 – July 19, 2021, 07:11:19 pm

Hi Keith, I'd be interested to hear back in a few weeks if this helps with the 84 10 over speed problem.

My error condition is so intermittent, it's impossible to replicate, but a huge headache until I can reset the check engine error. Reseting it in VMSpc doesn't clear the engine ECM log, I was told. Would like to resolve if possible.

Thanks in advance for following up.

Re: Check Engine Light On 84 10 Road Speed error

Reply #19 – July 19, 2021, 07:41:09 pm

I only had the code come up one time and have driven about 1000 miles since then without a repeat, but I do see the speed signal fluctuating a few mph (on the VMSpc). Cruise set at 70, it flickers from 67-70. Replacement sensor ordered. Next trip is 3 weeks out.

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