'Thud' now a 214 code shows

[Joe Dirt]

So driving home today, I merged on the highway, and when letting off the gas after getting up to speed, I feel a thud, which could have been a backfire- I really wasn't paying attention for it, so I'm not sure, since it was over before it registered in my brain.

After that, the CEL comes on for about 30 seconds, then goes out. Tonight I pulled a Memory code 214. The truck still runs fine, no acceleration issues, etc...

I'll probaly go to the boneyard this weekend, there is a 60K mile 1997 OHV there, I can pull the Cam and crank sensors off it if I need one, but has anyone experienced this? What happened?

I should add that ever since I've had the truck, when idling I can once in a while feel a very slight random miss- Maybe 1 or 2x at a traffic light- but never a hesitation, or any drivability issues, if that is topical.

Truck idles at about 500rpm on all 3 clusters I've had in the truck.

TIA!

PS- I pulled: 114, 539, and 214 for codes, the 214 was the only memory code...

 

[BrooklynBay]

This list is from # 17 in my list of useful threads: http://www.explorerforum.com/forums/showthread.php?t=160035

114
(O,R)
IAT sensor out of range - IAT.

214
(M)
Error in Cylinder ID (CID) circuit or signal - Ignition Systems.

539
(O)
System shows voltage at PCM pin 10 Is A/C on?

 

[Joe Dirt]

Any thoughts about if the thud is related to the code, or if anything other than a worn Cam position sensor is throwing the 214? Snowball drove just perfect to work this morning, about 12 miles, highway included. No CEL thrown either.

...but I know I just jinx'd myself by saying that

 

[BrooklynBay]

I don't think it was related. How old are the spark plugs, and cables?

 

[Joe Dirt]

Well, when I bought the truck, there was documentation that they were relatively new. (Within a few months) but everything was dusty, so not sure exactly. I'm thinking about changing them just to know for sure that they are new since this is now my DD.

Also, today I stopped to get gas, and started the truck, it idled low for a second, and stalled out. After that, wouldn't start twice. Sat about 10 seconds, and it fired up and drove normal. It did this a couple months ago at AutoZone, and hasn't done it since. Could it be a crank sensor maybe, and thus the code 214? I don't know if I had cleared the codes after the AutoZone incident...

Hmmmm...

 

[MrShorty]

As I understand the '95 system, a CM214 points to the camshaft position sensor (CMP) circuit rather than the crankshaft position sensor (CKP), if the '95 even has a CKP.

How consistent is the CM214? If you clear the code and test drive it, does the CM214 immediately come back?

 

[Joe Dirt]

I'm not sure- I didn't have a chance to run the codes yet tonight, I'll run them in the morning when I get to work. Had to set up the Plasma... I didn't get a CEL today though.

 

[Joe Dirt]

Ok, now it gets weirder. So today I stop for gas, and when I pull off, I decide to stop and get a Pepsi inside. So I park, shut off the truck, and as soon as I shut it off, I decide- no, I'll let it run so I can get some heat in here. Of course- it won't start. I notice this time, that the oil presure gauge is fluttering all over the place, and it will not start. My gas mileage sucked as well, now.

So, as before, let it sit for 10 seconds, key all the way off, and voila- next time, it starts. Truck runs perfect.

So I ran codes when I got home, and I get:

KOEO:

114- IAT out of range (Truck was warmed up)
543- Fuel Pump monitor circuit shows no power - Power / Fuel Pump Circuits

KOER:

538- System did not receive goose test (didn't goose it high enough)
536- Brake on off open or shorted to ground (?)
632- TCS should be cycled between engine ID and goose test

So does any of this matter? As seen, it's been 2 days and about 45 miles, and no CM214 code, so I think that one may have been a fluke or isolated at least.

Also- when I owned my 1997 SHO, when I had bad coilpacks- the car would stall, and would not start back up until I cycled the key all the way off, then back on, and the gauges would flutter if I tried to start it before I did- just like Snowball does. Does it make sense that maybe I have a bad coilpack? Could that explain the random misses as well? The SHO had those too- the Truck does not stall on it's own at stoplights like the SHO did, but everything else is the same. I know the Ex isn't Coil on Plug like the SHO was, but it sure seems eerily similar now that I think about it.

Thoughts?

 

[BrooklynBay]

Clean the MAF sensor, check the PCM's ground wire for rust or corrosion, and check the power wire coming off of the PCM relay with a volt meter the next time it doesn't start. I suspect that a bad connection will allow the CEL to show when it stalls, but it might not have sufficient voltage to power the PCM correctly. The other idea is that the MAF sensor has a dirt build up, and is cauing these issues.

 

[Joe Dirt]

Is the PCM ground the one or two black wires that come out of the giant harness that plugs into the PCM bolting to the firewall?

I'll clean the MAF as well tomorrow, it'll be about 50 degrees here tomorrow, so it'll be a good day to putt around on Snowball.

Thanx!

 

[BrooklynBay]

The PCM wiring should be located near the battery. Check a wiring diagram to be sure.

 

[MrShorty]

How cold was it in MI when you ran the test? I wonder if it was cold enough to cool the IAT in the brief interim between stopping the engine and setting up the KOEO test. Maybe not worht worrying about right now.

You didn't list CM codes, so were those KOEO codes before the separator pulse, after the separator pulse, or both?

With a no start, or intermittent no start, I certainly wouldn't ignore a KOEO 543. When it won't start, does the fuel pump run? I would almost certainly take the time to put a voltmeter on the fuel pump circuit at several points to see if I could figure out why the computer isn't seeing power on the fuel pump circuit.

Those KOER codes are all operator error type codes, you just need to review the test protocol and repeat the test with the proper actions taken.

 

[Joe Dirt]

Ok, this stuff is still going on. I've cleaned the MAF, but have the following codes:

-KOEO (After pulse)
-539 System shows voltage at PCM pin 10- A/C is NOT on.
-214 Error in CID circuit or signal- Ignition System

KOER
-116 Engine Coolant (ECT) out of range

This was after I got to work, and the truck sat for about an hour, but should have been warm.

What's triggering the CEL is the single stutter. Happens on maybe one out of 5 drives now. I will be driving on the highway, cruising like this morning. Not accelerating or decelerating, just "holding speed" no cruise. The truck will "miss" once, and then the CEL will come on. Usually goes out after a couple minutes, and won't come back until it does it again.

When I am at a light, it will slightly "miss" a few times during the course of a light, it will not trip a CEL, but I can feel it- it's been doing this ever since I got the Ex.

I have a spare coil, should I put it in? My mileage has been 12-14 MPG but about 1/3 of that time I was in ControlTrac auto, so it could be using more fuel?

I have not had the stall issue since, but when starting the truck, I hold the key slightly longer to make sure the start "takes" for the lack of a better term. A few times it idles roughly at about (on the tach) 300-400 RPM, but recovers after either revving a little bit, or driving. After that, it's fine. 90% of the time it starts and idles fine though. According to my tach, Snowball idles at about 400-450 RPM, and that's on 3 different clusters, all the same RPM reading.

Anyone have a similar issue pop up and fix it?

 

[MrShorty]

Too much to copy the entire circuit test over, but here's the introduction (from Mitchell's repair manuals. You can often find them or similar at your local library).

CID signal provides PCM information for fuel injector synchronization. The CID signal is generated from Camshaft Position (CMP) sensor. Enter this CIRCUIT TEST only when instructed during QUICK TEST. This test is only intended to diagnose:
* CID +, CID -, CID, SIG RTN and VREF wiring harness circuits.
* Camshaft Position (CMP) sensor.
* Powertrain Control Module (PCM).
1) Continuous Memory Code 214
Code 214 indicates error has been detected in CID sensor input signal. Error could be due to a hard fault or an intermittent fault. Possible causes for this fault are:
* Open or shorted wiring harness.
* Faulty CMP sensor.
* Faulty ICM.
* Faulty PCM.

I don't think changing the coil pack is going to do anything, because the coil isn't involved in a CM 214 on a '95. Do you have other reason to suspect the coil pack (Cracks, out of spec resistance readings, etc.)? A bad coil pack could certainly cause a misfire, but I'm not sure that a misfire would be enough to trigger a CM 214.

For the KOEO 539, you say the AC isn't on, but is it in Defrost mode? I believe on a '95, the defrost setting automatically turns the AC on.

It seems that each of your posts has a little bit different list of codes. When you start getting a lot of different codes inconsistently, I might start looking at things like the main EEC-IV power supply or grounds. I've seen bad grounds cause a lot of "ephemeral" codes like that. It might be worth the 10 minutes to verify that there's no voltage drop across the ground wires.

 

[Joe Dirt]

I think I had thought to replace the coil because of the miss. The plugs and wires were new 6 months ago, and something has to be causing the miss.

Yep, it was on defrost. Damn. Ok, fixed that one.

The 214 code has always been there... But I will clean all of my grounds this weekend.

 

[scrappy983]

Hey Joe, wondering if that 214 ever went away. While I'm driving down the road, using enough accelerator to maintain speed, I can feel the 95 Ex surging. I fell it power up a little, barely changing RPM, then slowing. Over and over. I pulled the 214 code. Cleared it. Pulled it again. Any thoughts?

 

[Joe Dirt]

It never got cleared up, and waaaay back then that 60k Ex in the boneyard had the sensor pulled out already. I ended up driving Snowball until I sold her this past spring, never replacing the sensor, never getting rid of the 214 code, and without any real consequence. I didn't want to spend the couple hundred dollars to get a new sensor.

The new owner replaced it after I found one at a junkyard, the code went away, but the truck drove exactly the same as before...

Also- I was incorrectly informed about the plugs and wires if you read post #5. I was told that they were new, but in fact when we changed them a couple of days after I sold Snowball, they were the original plugs and wires at 230k+ miles. Still had the assembly line white dots on the plugs too.

Once those were replaced, it did drive much better, but no consequence on the code.

 

[scrappy983]

Code just went away. Thanks for the help though