[rtb]

Hi guys. I'm hoping someone can give me some diagnostic help. :huh:
Mine is a 2003 Heritage Classic. I'm getting these errors intermittantly:
P1356 Rear Cylinder No Combustion EFI
P1358 Intermittent Secondary Rear EFI

They happen about 1-2 times per week while driving in 5th gear at highway speed (60 - 70 MPH) on flat road (no heavy load). I don't ride hard. I feel no engine miss, but I'm sure the computer is more sensitive to misses than me. The bike starts/runs just fine. These errors started about two weeks ago after I did these things:
- Every one of the 15k service items including new spark plugs.
- I changed the stock mufflers for Screamin Eagle torque mufflers (p/n 80388-01).
- Washed the bike with hose/water (my usual method) and dried with an electric leaf blower.

The engine light comes on but turns back off after about 30 seconds, so the errors are stored as "historic" trouble codes.

I have all of the manuals and followed the instructions for these errors in the Electrical Diagnostic manual. I see no signs of "carbon tracking". Resistance of the spark plug wires are right in middle of the spec. (rear = 2.6k ohms and front = 6.1k ohms). I don't have a "Harness connector test kit", p/n 41404.
- Can I somehow proceed through the yes/no maps w/o this "Harness connector test kit"?
- What are typical causes for these errors? Could I have a new defective spark plug?
- I DID NOT have the ECM mapped after replacing the pipes. I am still using the stock air cleaner. Could new pipes cause this?

I enjoy wrenching myself and don't have a warrenty on the bike. I hoping to fix it without a trip to the dealer. I sure would appreciate any advice. Thanks in advance.

 

[Teufelhunden]

I have had no combustion codes thrown by a fuel mixture ever so slightly off. Not enough to really feel, but once richened up, problem went away.

Teu

 

[bbrowncods]

I've heard that if you use spark plugs other than stock HD these codes may pop. Also check the coil.

 

[rtb]

I have had no combustion codes thrown by a fuel mixture ever so slightly off. Not enough to really feel, but once richened up, problem went away.

Teu

Teufelhunden...you mean that you HAVE had combustion codes? You think running lean due to pipes might be the problems? Thanks.

 

[rtb]

I've heard that if you use spark plugs other than stock HD these codes may pop. Also check the coil.

Yeap...I heard that too. I used stock Harley plugs for the replacements. Thanks.

 

[Teufelhunden]

Teufelhunden...you mean that you HAVE had combustion codes? You think running lean due to pipes might be the problems? Thanks.

Yep, reread my previous and guess it was not clear. I have had the "no combustion" front and rear thrown by a slight lean condition.

Teu

 

[rtb]

Yep, reread my previous and guess it was not clear. I have had the "no combustion" front and rear thrown by a slight lean condition.

Teu

OK..thanks. I plan to pull the plugs for a look see. Maybe the plug color will help determine if the pipes are making it run lean. When I replace the plugs I took the old ones to the dealer for a second opinion. The service guys said that according to the plug color the bike was running perfect. This of course was with the stock pipes prior to the new torque mufflers.

 

[rtb]

sedelux05, thanks. I got new stock plugs from the dealer today to put in this weekend. While doing I'll check the stuff you mention. I bought a twin cam 88 scanner from daytona-sensors. I logged data from my drive home from work today. This is neat but I'm not sure what to do with all the data.
Anyway...anyone got any other ideas?
Thanks.

 

[bbrowncods]

bb how does the ecm know that they are not hd plugs. i beleive hd plugs are autolites or champions i switched to ngk $2.00 apeice had se platnium 15.00 for two the only one who felt the diffrencewas me . the trouble code might getting tripped due to a loose wire from vibration at highway speeds. check the spark plug wires and all connections if its only reading on 1 cylinder id bring it back to the stealer and ask them to check it out for you

Just sharing some of the info from this great site. Also the service manual and owners manual mentions only using original plugs. Maybe others more knowledgeable can answer how the ECU can tell. I think it has to do with the knock monitoring. Not sure on that though. Here is an actual case from the forum. There are more accounts of plugs fixing these codes. A search for "plugs P1358" will yield more.

Had my 04 Road King Classic to the dealer today. Turns out what was caausing the bike to throw the codes was that I was running non-Harley plugs. I have to do with the dealer on this one. They checked out everything else. And it makes since because i first started having the problem after I installed a set of Champion plugs. I suspected the plugs and relaced the Champions with a set of NGK's. The dealer installed a set of Harley plugs and ran the bike for over a half hour on the dyno and could not get it to throw a code. I have also visited with a very reliable tech on another forum and he agrees with the findings.

So anyone out there thinking of changing plugs, you might want to reconsider if you are buying something other than Harley plugs.

 

[Rkpickett]

My '04 Ultra used to throw the same codes. Dealer told me that I was not holding the starter button down long enough after a 'heat soak' re-start and a slight kickback was the problem. Well, that fixed my problem, seems I remembered doin that once or twice after a long hot ride. Also I read somewhere in this forum that too much anti-sieze on the plug threads messes up the ground path and the coil / ion sensor sends the signal to store the code in the ecm. Anyway, no more codes for me... Rick

 

[rtb]

My '04 Ultra used to throw the same codes. Dealer told me that I was not holding the starter button down long enough after a 'heat soak' re-start and a slight kickback was the problem. Well, that fixed my problem, seems I remembered doin that once or twice after a long hot ride. Also I read somewhere in this forum that too much anti-sieze on the plug threads messes up the ground path and the coil / ion sensor sends the signal to store the code in the ecm. Anyway, no more codes for me... Rick

Rk...when you were not holding the starter button down long enough; did the error set immediately after starting? Thanks.

 

[rtb]

Thanks for replies from you guys. I changed the plugs today.
The plugs I pulled looked good. The rear plug indicates that rear cylinder is running just a little leaner than the front, but
not enough to be a problem I think. This is an intermittant problem so I'll just have to wait to see if the problem happens again. I'm suspicious of the new pipes without remapping the EFI may still be the problem.
Any other ideas would be appreciated.

 

[Rkpickett]

Rk...when you were not holding the starter button down long enough; did the error set immediately after starting? Thanks.

Seemed like the check engine light would come back on after the next or second re-start, but since I started paying attention to hold it down past the 'kick-back' point untill the engine was fully running, no problems.

 

[rtb]

Seemed like the check engine light would come back on after the next or second re-start, but since I started paying attention to hold it down past the 'kick-back' point untill the engine was fully running, no problems.

Thanks. I'll start paying attention to that.

 

[Chip_3]

I dont really question any problem with non HD stamped plugs, but what I do after 40 years on a bike and had many problems is getting into the habit of looking and trying things, one habit that is a goer and really makes a diff with spark plugs and you know the diff when you hop on and go is, any time a spark plug is removed or replaced I index the plug, this is done very simply by usinf a fine line texta mark on the outside of the plug on the ceramic part facing the closed end of the tip, the plug is then screwed into the head and only tightened so the texta mark faces you, this indicates a indexed plug and both will be facing towards the centre of the 2 valves. remember taking out the old plugs was not first marked therefore you have no idea of the original position.

 

[rtb]

fixed!

Maybe this will help someone else. I fought intermittent P1356 (Rear Cylinder No Combustion EFI) and P1358 (Intermittent Secondary Rear EFI) for a long time. I’ve read here that others with 2003 vintage EFI have had the problem also. After finally capturing a few of these errors with the twin scan 88 (set at .2 seconds log interval) it appears that the error is set when:
1) The Throttle is at 100%
2) The RPM is rising to about 3600
3) The MAP is at 30 In-Hg (100 kpa)
4) The rear knock logic has just risen to between 4 and 8 degree.
5) VSS is rising from 50 to 70 MPH
In other words when accelerating to pass on the highway for example. Using the SERT, in the 2500 to 4000 RPM range rows and 90 and 100 MAP columns cells of the “Spark Advance Rear Cyl (Degree)” table I reduced the timing by 7 degrees. This represents 10 cells. This seems to have fixed the problem!

 

[Bluescb]

I first got those codes on my '04 RKC after I had the dealer do a 95" build. They put in Splitfires. I tried all kinds of plugs.. no help. about 15K miles later, I took my heads off to have them worked on. Of course, I had to remove the spark plug cables form the coils. When I put it back together, using the Same plugs that would throw the codes before, I didn't get the codes! I REALLY think the ECM is so sensitive that the slightest vibration from the wires to the coil will throw the code. Unhook and clean the cable end and where it plugs into the coils and see what happens. I also read on the HH site a LONG time ago about Harley knowing about this and late '03 to about May of '04 ECMS were the bad ones. Hope this helps

 

[Coolmaker]

Replace the plug wires and make sure they are plugged on tight to the plugs. I run NGK's and have no problem with them. Have left a plug wire loose and had it happen..

 

[fauskar]

2004 Twin Cam Combustion Codes

This applied 04's.
~~~~~~~~~~~~~~~
May 31, 2004

There have been reports that some production 2004 EFI Twin Cam vehicles intermittently set codes P1353 and P1356. These vehicles were stock and had no driveability issues. An investigation determined that the 2004 ECM calibrations may allow these two codes to be set without any actual combustion problem. Calibration changes correcting this potential issue went into production vehicles built after May 3, 2004.

The revised calibrations are included in the Digital Technician software, version 12, recently shipped to your dealership.

Although rare, it is possible to encounter either or both of these codes on a stock, production 2004 Twin Cam vehicle built prior to May. If so, simply download the new stock calibration using Digital Technician then file a warranty claim for labor in the normal manner using Job Time Code 7931.

 

[lstbkr]

I have had this problem with my 04 ultra for 4 years now. The fix I use is to run fuel injector cleaner thru 2 or 3 tanks and it goes away for 4 or 5 months. I think its just a dirty injector with a weak pulse that sets mine off.