** How to diagnose your AEM WB Gauge/Sensor combo **

[Internexus]

Purpose: This little tutorial will not only show you how to quickly test both your AEM Wideband gauge but also the sensor. Once you determine which one is faulty obviously you can replace it accordingly, however I have also included a cheaper alternative to replacing the sensor instead of paying for the semi pricey AEM sensor!

Problem: My gauge is stuck at ~14.7 and doesn't move whether WOT or cruise, what's the deal?!

Answer: The gauge being stuck at ~14.7 signifies typically that the signal is not being transmitted properly.

This could be 1 of 3 things:

1) The wires are disconnected/broken between the sensor and the gauge.
2) The gauge has gone belly up.
3) The sensor is finally toast.

Solutions:

1) You should know how to check this yourself fairly easily so I won't elaborate.

2) Disconnect the 6 wire plug from the back of your gauge, and measure the voltage on the white wire and check to insure it is near ~2.40 volts. If it isn't picking up anything at all make sure the connection is good and if so then your gauge is done for.

3) The quick way to test your sensor is to turn the key to the on position, the gauge will quickly go through it's various output readings then go to ~14.7. As the sensor heats up if it's in functioning order it will slowly begin to start reading more and more lean until you end up with '---' as your final reading. This shows the sensor is functioning correctly.



This is your standard O2 sensor for the AEM AEM Power 30-2001 - AEM Power Replacement Wideband O2 Sensors - Overview - SummitRacing.com sitting at $80 + shipping.

You can purchase a 17014 Bosche O2 sensor from your local autoparts store for a whopping ~$50.

Here's the How-to on making it work with your AEM gauge!



The parts: You will need your old o2 sensors and your new one.




The tools: You will need some dikes, soldering gun, solder, heat shrink tubing, a lighter, wire strippers, and 1 great smelling candle for that fine feminine touch!




Begin by taking the AEM o2 sensor and pulling the protective sheath away from the connector roughly 4-6 inches and cut the wires. Proceed to strip the ends and prepare them to be soldered as well as put your heat shrink tubing on now so you don't forget to later.




If you look at the first picture you can tell the replacement o2 sensor has a lot of excess wiring so I cut the zip tie in the middle and got rid of the second half of the length to bring it close to the same amount length as the AEM unit. Obviously we want the bulk of the length on the o2 sensor portion here and I pulled back the sheath far enough that I made my cut and the sheath would cover up all of the wiring from the AEM connector as well. Use a small binder clip to hold the wires back while you prep them.





Solder everything together and put your shrink wrap over the connections.




Zip tie the sheath to the end closest to the AEM connector to keep it from sliding around on you and you are all done!




Install and test it out with the procedure listed above!

Happy tuning!

Sean

[mb3000]

Good stuff, thanks for posting up.

[DocWalt]

Nice guide, thanks for the post

[BaadVR4]

Interesting. My wife's car had an alternator fail, putting 19+ volts at the battery at idle. When the alternator failed, the stereo quit working and the AFR would peg lean whenever the engine was revved above 3000 RPM. Replaced the alternator. AEM tech suggested driving it for a week and see what happened. She drove the car for several weeks and the AFR would occasionally peg lean. As we continued to drive it, the gauge kept pegging lean more and more often. Since the gauge cycled through its "start up" like it was okay, I changed the O2 sensor. Problem solved.

[GTOJOE]

Did this work with no issues? One of the guys here in Australia did somethign similar to this with his O2 sensor and soldered the connections. He was having wierd issues with the car and couldn't work it out and the mechanic found his repair and told him O2 sensors cannot be soldered and should always be crimped only as the soldering effects the resisotance of the wires and causes issues....... I thought it was very strange as any difference would be tiny. I might have to dig up the old thread and try to get the full story.

Has anyone heard this before? or is the guy on crack?

[Internexus]

I haven't taken the car for a test drive yet but I can tomorrow if I have time and let you know how it reads in comparison to the other wideband (I have one for each bank).

[deemo99]

Did this work with no issues? One of the guys here in Australia did somethign similar to this with his O2 sensor and soldered the connections. He was having wierd issues with the car and couldn't work it out and the mechanic found his repair and told him O2 sensors cannot be soldered and should always be crimped only as the soldering effects the resisotance of the wires and causes issues....... I thought it was very strange as any difference would be tiny. I might have to dig up the old thread and try to get the full story.

Has anyone heard this before? or is the guy on crack?

Ever get an answer to this? My first install of my wideband was not all that good and I melted a couple of wires on the exhaust, D'oh! I have also read what you heard somewhere as well and also find that unusual.

Anyone else know if soldering or crimps is the way to go? I plan to contact AEM as well, but thought I'd ask here too.

I should add that the damage to my wiring is after the sensor connection, about 18" or so toward the gauge.

Thanks!

[Boostaddict]

FYI, lots of people have had issues with cutting/soldering the AEM wbo2 sensors/wiring. In years past AEM would tell you NOT to cut the wires under ANY circumstance (to shorten or get the harness connector through the firewall for instance). Not sure if their stance has changed, but I'd go through the extra effort to swap the connectors by de/re-pinning before I cut/soldered the wire. Good effort though!

[DrGonzo]

This will not work!! You Gauge will not read correctly if you splice in a new sensor or shorten/cut/splice the wires!!!

This is because the sensor is calibrated as is from the factory and specific to the AEM gauge. Replacing the sensor like this will not work and the AFR will be out of calibration!

The AEM plug has a set of resistors in it that are calibrated to exact sensor and wiring they sent you. They all have a laser cut code on the plug which specifies it's calibration. The new WB sensor you bought is not calibrated to the AEM gauge so it will not be correct. Even cutting/soldering the wires would throw it out of calibration.

You can reference page 3 of this manual for details" http://www.aemintakes.com/instructio...-4100_inst.pdf

[deemo99]

Talked to AEM tech today, he recommended I simply twist the wires together and tape them. Not sure this is the best for the run from the sensor connection to where I have the wires running into the car (through the grommet under the drivers seat). I sent an email asking for pricing on a new sensor harness, no answer yet. Not excited about swapping out the sensor harness since I have the gauge in the stock location, not sure if I can even swap that out without pulling the freaking dashboard! If I have to I will since the WB is needed.

Moral of the story, don't do a crap install on your wideband wiring, you'll regret it. I may try spark plug wire protectors to keep from melting again...still looking into options for protecting the wiring from the exhaust. Anyone go over the factory heat shield? Not sure of the temp difference over vs. below.