To the OP, maybe this thread will help:

https://www.scionlife.com/forums/sho...ng+harness+tsb

The TSB fix is to replace the main wiring harness. It applies to early 2008 XBs including mine but I haven't had any of the symptoms. It could help explain why the AEM FIC and APR-X1 didn't work on my car when they appear to work fine on other XBs and TCs. In 48k I haven't had a coil failure. I'd rather trade my car in than let the dealership butchers attempt something as complex as a main wiring harness replacement. Good luck and sorry for the threadjack.

 

Thanks for the link ScionFred. That thread got me to a bunch of guys having the same & related problems involving a TSB on the engine wiring harness which was replaced early on in my car. I'm thinking somehow there are more electrical gremlins loose involving the coil failures.
Here's a quick history of issues I've had.

2008 xB purchased 02-13-2008 – (VIN earlier than 91067111)
04-30-09 - 16,816 miles; Replaced Engine Wiring Harness per TSB Part#82121-12510
Switched coils 1&3.
06-19-09 – 17,104 miles; Code PO351 Replaced Coil #1 Part# 90919-A2001
09-15-09 - 23,727miles; Code PO351 Replaced Coil#1 Part#90919-A2001
01-06-10 – 25,512 miles; Code CO210 Replaced Right Rear Wiring Harness/Skid Control
and Hub & Brake Assembly. Wire Part#89516-12051 Hub Part# 42450-12090
05-15-11 – 39,644 out of warranty Code PO354 Replaced Coil #? Part#90919-A2001


So mine is 3 coils & counting... to the tune of $307.44 each at dealer now.


This is the 1st Toyota I've owned. Would be ironic if it became a dud since Toyotas have such a great mechanical reputation.

 

is this intermititent? or runs funny all the time.. take that coil 1 if happends again and swap it with coil 4 and see what happends.. Im pretty sure that coil is still good.

 

my car falls within the bad wiring harness period. Mine started out on coil A I switched them and seems like its now coil B. But i switched so much now IDk where I started.

I knowthe problem occurs after the car gets warm. I can drive maybe 10-15 min and boom it runs like garbage due to Traction control. It started out with months between faults. Now it does it every day. I am a entry level ford tech so I know little. However IDk where to begin with my DMM on this type of intermittent fault. Any tips appreciated I cant pay dealer.

 

what code didyour xb throw, im gettting a ecu/ecm code -_-

 

my code was a p0301. I finally was able to get on alldata and the TSB for the misfire code says replace coil. Coils were made cheaply basically. Idk where all this wiring harness stuff came from. I still cant figure out what in a harness would cause that problem. Im just a beginner tech so I know very little. For me though as I mentioned it happens as car gets hot so seems like a faulty coil. What in a harness can go bad from getting hot.

 

It seems to me that the wiring harness problem is not so much that it causes coil failures or other actual faults. As I read the TSB the harness causes false CELs (MILs) to appear, which can cause real problems as the ECU thinks that there are real problems. P0301 is mis-firing on #1 cylinder. I would switch coils between #1 and #4 and see if you get a P0304. If the coil really is bad, you should.

Also, I just saw a coil tester on Pat Goss' Garage that may be worth a try. IIRC he said that they are only ~$15 at most auto parts stores. I used to remove a plug and hold the ground electrode to the head while cranking the engine but this tester replaces the spark plug and allows you to see the spark more clearly. Might be worth a shot given the cost of new coils.

This looks like the tester Pat used:

http://www.brandsplace.com/0384-thx458.html

I've got the bad harness as well but so far (48K) the main CEL I get is an occasional P0101 (MAF range) although I've had P030x misfire codes before as well. I just reset them and they never came back after I removed the AEM FIC that caused them.

 

Ok so I replaced the coil today. And to my dismay I actually have two faulty coils. I work at advance so at least i get em at a good price. I checked my code and it was coil D. So I replaced that one. Then I jumped back into the ride and went for a spin. All was well for a little while till it continued to heat up. After about 5 min CEL came back and the god forsaken traction control kicked in. I hate that crap making be barely able to go.

Anyway I pulled the code again and it was Coil B now. I moved it to Coil A and it immediately followed. So I have a second coil failure. Which makes sense because When all this started I moved the coils to see if fault followed coil or not. After a short time it seemed to move but I figured at this point it was the harness I read about. I feel dumb my car been sitting cuz I thought i was gonna have to buy a harness. Looks like its only a few hundred dollars in coils.....yay! Im really upset about Scion

 

Excessive plug gap is hard on coils. Scion recommends .043, new plugs come gapped to .044. When I replaced the ND iridium plugs in my parent's 2AZ-FE Highlander at 75k miles the gap was well over .050. Part of the TRD SC kit is 1-step colder plugs gapped to .032.

If I was experiencing a high rate of coil failure I'd consider reducing the plug gap to make life easier on the coils. Because I'm turbocharged I'm running 1-step colder NGK iridiums gapped to .032 and no coil failures to date (47k). Although they say you can't re-gap iridium plugs, you can. You just very carefully bend the ground electrode to the desired gap without touching the fragile center electrode. For a N/A 2AZ I think I'd start at .040 which should open to about .045 after 50k miles.

 

anyone try adding a nology wire set?

 

Received a recall today which is for replacing four ignition coils. Same trouble codes as mentioned above.

 

Is this recall for all the 08's?? Do I have to go to the dealer to check up on this?

 

Me too.

If you didn't get a notice just go down to the dealership and check.

 

Had my 4 coils replaced under the recall Nov. 30th.

2008 with 97,xxx miles on it.

 

my 08 falls under the problematic harness and these coils. I want them changed out but im not throwing any codes, even working at a dealership wont get me that kind of treatment. I guess i need to wait it out.

 

I got my notice today about the recall. I will take it in a few weeks to get repaired.

 

I've never had any problems with my coils or thrown any codes either. When I called to schedule an oil change, they told me "open recall, you get new coils for free."

 

ill have to bring it up to a writer tomorrow. Id love to get them replaced, i have a road trip coming up too. Ill report back.

 

Hey everybody,

Just for clarification: Yes, there is a recall titled "(LSC) B0K
Certain 2008-2009 Model Year Scion xB Vehicles Ignition Coil Replacement" and Toyota dealers will replace the ignition coils at no cost to the customer.

Also, if you had already paid to have the ignition coil(s) replaced and you are under this campaign, you can submit a copy of your invoice, proof of payment and proof of ownership for reimbursement.

Owner notification began in early November. If you have any questions, feel free to PM me or give us a call!

Thanks,
Jenn

 

kit in stock here.......