robw01

I recently installed an aftermarket exhaust. 500 miles later the CEL came on. I was searching through the site like crazy and nothing really seemed to apply. I had the codes scanned and they are as follows....

1298 - High voltage detected
0135 - Primary O2
0141 - Secondary O2
0411 - Secondary air flow something or other

This led me to believe there was a short around the CAI (it's been on the car for 2000 miles) and Air Control Solenoid. Sure enough, one of the plastic clips holding the wiring harness for the ACS away from the engine had given way. The wire was right up against the alternator pulley. I can't believe I missed it on first inspection, but that's neither here nor there. The alternator pulley had eaten through the plastic loom and the wiring insulation.

I repaired the wiring, but I'm still getting a CEL. In my mad search for exhaust related CELs I came across a post from someone who had the same ACS wiring short. I dismissed it thinking that couldn't possibly be my problem. Now I've been searching again to find out what all he/she ended up having to replace. I cannot find it!!! (I love s2ki.com, but the search functionality blows.)

Anyone know the thread I'm talking about? Any idea what I'll need to replace? I figure I'll get the codes scanned again to make sure the 1298 is gone. Then I'll replace the ACS. If that doesn't work, both O2 sensors. Then finally if all else fails I'll replace the ECU.

This has seriously ruined my weekend.

robw01

Follow up...

Just had the codes scanned again at the friendly neighborhood Autozone. The 0411 is now gone, but the 1298, 0135, and 0141 remain. I also noticed that it didn't crank over as well when leaving Autozone. Could I have fried the alternator and hence the 1298?

Slows2k

P1298 is ELD (electrical load detector) cicuit high voltage.
P0135 is primary O2 sensor heater malfuntion
P0141 is secondary O2 heater malfunction.
P0411 is secondary air injection incorrect flow
The P0411 has a 2 trip monitor, So It can take 2 drive cycles before recoding. The other DTC's are all hard failures. What wiring was damaged to the alternator? was is the wiring to the back of the alternator or was is the wiring to the air control soleniod that is right in front of the alternator? The P1298 can be caused by open wiring between the ELD and the 15 amp fuse marked ACG, or between the ELD and the PCM. The ELD is located in the passengers side fuse box. It is brown with a 3 pin connector plugged into the top of it. I would check the ACG/alternator fuse 1st. Then make certain the wiring that was damaged is repaired correctly. Allthe wires are connected well and to the correct places. I don't have the wiring diagrams in front of me, It may be possible that the power feed for the O2 heaters comes off the alternator. I which case you may need some pricey O2 sensors. Did you remove any O2 for your exhaust install? If not I would say that the exhaust has nothing to do with your problem. You could be in for some costly repairs.

robw01

The wires that were damaged were the two wires leading to the Air Control Solenoid. (They are right in front of the alternator.) The insulation was worn down by the spinning alternator pulley. Eventually bare wire became exposed and shorted to the pulley. (The red wire was almost eaten through by the time I caught it.)

I won't have a chance to get back to the fun until Monday. I'll definitely check the fuse. Hopefully it will be something that simple, but I'm not going to bet on it!

The exhaust was a cat back deal. The O2 sensors haven't been touched.

robw01

So far so good... Thanks Slows2k!!!

As Slows2k suggested, I checked the ACG fuse before doing anything else. It was blown! I replaced the fuse and let it idle for 10 minutes. During that time it reached 3 bars on the temp gauge. It idled extremely smooth and the check engine light never came on.

FYI... In the Helm Service Manual's troubleshooting flowchart for code 1298, it says to check for an open from Fuse 6 (ACG 15amp) to ELD. Fuse 6 is the 20amp windshield wiper fuse. I'm sure they meant Fuse 8, which is listed as the 15amp ACG fuse in the owner's manual.

I'm confident the 1298 code is fixed. It looks like the 0135 and 0141 were also related to this circuit being open. The trouble shooting for those codes includes checking for an open at Fuse 6 (really fuse 8) as well.

Thanks again for the direction!!! I appreciate it!

Slows2k

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