check engine / ASR

[sheward]

No brain stumper here, just looking for some educated opinions and knowledge.

Symptoms: check engine light illuminated.
Also, under full throttle ASR light comes on and stays on until a restart. The car runs normal under both these circumstances.

I finally got around to pulling codes and ran into trouble. First, my blink box broke, and I'll need to solder in a new button. 2nd time used. Garbage. More importantly, when I turn the ignition on to begin testing there is a high-pitched squeal similar to the "key in ignition" sound only not as loud. It is there continuously and emanating from the ETA. There is also a continuous soft pecking sound repeating about once a second. This does not sound like anything I remember hearing before. This is not to be confused with the cycling of the ETA which I can hear about 10 seconds after turning the ignition on.

Does this just seem to indicate a problem with the ETA? It was changed recently but I'm unsure of who may have rebuilt it and not above suspicion. I have other ETAs and will be sending one off to Don Roden this week for rebuilding. I find this situation strange because as said, the car is running well.

Thoughts?

 

[gsxr]

Drew, for the CEL, there is a built-in button and LED to check codes with - no need to use a separate blinker box. That will tell you which code is causing the CEL at least.

For the once-per-second pecking sounds, any chance it's from the purge "MOT" valve near the EGR?

You'll need a blinker box to see what is causing the ASR fault light. If it isn't triggering limp mode, it miiiight be the brake light switch.

What brand/vendor did you source the poor kwality blinker box from, btw? Photos?

 

[sheward]

Very helpful. I'll have a look at the built in LED.

I'm not sure I know without a look up where the EGR is but the sound sure seemed to be coming from the ETA area. I'll check again.

While wiring the new sound system I had all the kick panels, carpet, etc. out. Maybe I disrupted the brake light switch. I'll look into this as well.

Here is a shot of the blink box. It worked OK once previously. I'm using a MB mushroom, so no issues there. I believe I bought the blink box from a forum member or local enthusiast.

Thanks!

 

[sheward]

OK. EGR is at the front of the intake manifold. The sounds, both of them, are coming from the ETA.

Does it normally take 10 to 15 seconds after ignition on to hear the ETA cycle?

To be fair, the blink box may have been used or abused before me. Pretty sure I did not buy it new.

 

[gsxr]

The ETA should hum immediately, but may take 10-15 seconds before it makes additional clicky noises as the clutch & throttle plate move. There might be some YouTube videos that show normal ETA noises. But there isn't generally a 1-Hz click, at least not from the ETA.

 

[sheward]

OK, then. I'm now only bothered by the constant "ignition on" high pitched noise from the ETA. I'll gather codes. Does the integral under hood blink box for the CEL function just as the plug in one, as far as reading codes?

 

[gsxr]

Does the integral under hood blink box for the CEL function just as the plug in one, as far as reading codes?

Yes - identical in function as the hand-held box, except the built-in bits are permanently connected to pin/socket #19 for the DM / CEL.

 

[sheward]

I'm now aware I have been overly concerned about the noises mentioned. They were amplified a bit thru the airbox which I had not removed initially.

I feel it may be helpful to diagnosis and educational to add the back story to this situation.

Some time back after exhaust work, I replaced the steel OEM donut gasket between the crossover pipe and the right downpipe with this composite one.

This donut quickly "disappeared"; it did NOT fall out so I can only assume it disintegrated from heat. I was far from home and had to drive the car some 40 miles with an exhaust leak, even after cinching the pipes together a bit. Soon, the car went into "limp" mode and everything electrical in the car began to fail. I did make it home.

It was 92 degrees and very humid. Later, after reading some comments about "can box over temp" codes I surmised that was indeed what was responsible for the car's meltdown. The hot exhaust gasses coming from the leak just below had overheated the can modules. After cooling down the car seemed normal again however this is when the check engine light began to show up, as well as the ASR light intermittently.

Present.

After clearing the existing codes thrown by the overheating and a complete inspection of the distributor caps, rotors, and insulators, I drove the car some more. The ignition inspection was unrelated, I just couldn't remember when I last looked at them and I have been experiencing the minor missing that's well documented with these ignition parts. If anyone is interested, I'll post what I found in my owners' thread.

Here are the codes, both before clearing and after.

The car is running great (ignition parts cured the small occasional miss), but the check engine and ASR lights continue to show up in a random manor, usually disappearing after a restart. Thoughts?

 

[gsxr]

Drew, it looks like the ones to worry about are pin 6 code 21 (ASR unit internal sensor A7/3s1) and pin 7 code 6 (NSS switch or adjustment). Either could be causing the ASR light which resets after cycling the ignition.

The CEL's are unrelated, one for air pump, the other for LH adaptation limit. The air pump (#4) is just annoying but doesn't hurt anything. The LH at the limit (#19) is unusual. Check fuel pressure at the rail with engine running, with FPR vac hose on & off, make sure that's in spec. Really need a digital scanner to view the adaptation values to determine what is going on there, blink codes aren't enough.

Edit: If adaptation really is at the limit, and fuel rail pressures are normal, additional diagnostics will be needed to determine why the adaptation is pegged - it shouldn't ne.

 

[sheward]

Thank you, Dave. My knowledge is weak in this area, and I wanted some direction before I plead with Johnathan to scan things. I'll make sure he sees this information.

I don't fully understand the adaption subject although I've followed discussion of it before. Question. Would driving the car with the exhaust leak effect the O2 sensor and cause a situation where the computer needed to re-adapt? I've also suspected the failed / melted donut gasket could have affected the sensor.

I drove the car three separate times after resetting codes, varying engine load. One of these runs produced no lights at all.

 

[gsxr]

I don't fully understand the adaption subject although I've followed discussion of it before. Question. Would driving the car with the exhaust leak effect the O2 sensor and cause a situation where the computer needed to re-adapt? I've also suspected the failed / melted donut gasket could have affected the sensor.

This is possible - a substantial exhaust leak upstream of the O2 sensor could have thrown off readings enough to mess with adaptation, if it was driven long enough with the leak. Not sure if the melted gasket bits could affect or damage the O2 sensor, but that's another possibility when other items are ruled out.

If you have time, reset LH adaptation by "clearing" code 1 on pin 4. This resets to zero/mean values. Now drive the car for a couple hundred miles, ideally over a few days and/or several cold start / warmup cycles. If CEL/DM code 19 goes away permanently, then it was likely the exhaust leak causing the code.

If code 19 comes back after a while, after resetting adaptation, something else is going on. Rail pressure is the easiest to check, you can buy an inexpensive gauge at the local McParts/FLAPS and DIY that part.

 

[sheward]

If the time I drove before I came to realize the donut was gone is included with the trip back home, it adds up to at least two hours of drive time. Varied driving, with high speed included. I wasn't immediately aware of the change in volume due to very little drive time with the new 5th Scale back pipe.
I have a new O2 sensor. I'll change it on principle.

 

[gsxr]

Sounds like a good plan. Make sure when installing the new O2 sensor, the lock ring of the electrical connector "clicks" into place. Sometimes this requires gentle use of Channel-Lock pliers to rotate fully into locked position.

 

[sheward]

The new 02 sensor made no difference.

I took the car over to Johnathans before the holidays and he ran a scan.
Stored code for an injector. Can't communicate with EZL. We also noted that the diagnostic plug in the can box seems to be breaking down. He recommended I take things apart and inspect and possibly rebuild the port. The interesting thing to me is that after the scan the car ran immediately better, with a completely smooth idle. This was NOT my imagination. No lights throughout the hour-long drive home. Next task is to swap Egas modules which I will do shortly.

Note. The car has always run fine. It just had a barely perceivable miss at idle.

The scan also showed some issue with the ABS unit, I believe he said a possible sticky solenoid.

I replaced all soft brake lines and bled the system, then drove the car and engaged the ABS with multiple hard stops with the hopes of a simple cure. The feedback thru the wheel tells me something is wrong, as if the left wheel is not in sync with the right. The car stops perfectly outside of ABS engagement.

Previously, just before coming to a stop, I have felt the left front wheel behave as if it was on a patch of ice. I have noted this happening 3 different times. I will now look to pick up a used ABS unit.

Note. After the panic stops to engage the ABS I restarted the car, which had been still running PERFECTLY and without cel, and the cel returned along with the ever-slight miss.

I'll update after Egas swap and re-seat, then try NSS replacement if that's unsuccessful. Thoughts welcomed.

 

[gsxr]

Drew, if your diagnostic socket is degrading, you'll need to replace it. Details are in this thread.

If a C3/C4 cannot communicate with the EZL and the diagnostic socket is good, that's either a faulty SDS MUX, or fault cable as Jlaa experienced & documented recently. It's not an EZL problem.

The ABS issue sounds like a PITA. If the same fault code keeps recurring, that code likely indicates the root cause.

What is the new CEL code appearing?

 

[sheward]

I have not pulled codes again yet. I'll do so and post before I go into the can box. I wanted to do the brake work since the car seemed to have improved. I was actually thinking this bit of info could add some direction. I recall reading once about replacing the diagnostic socket and I may have bought one. I'll have to look. Thanks for the link and trying to help using my third person knowledge.
The CEL all started with the heating of the can box so I'm hoping I'll find the issue with or under the modules or the port.

 

[sheward]

After re reading that earlier post on the port I am very curious to the condition of mine and optomistic about finding the problem. My car spent at least 2 years in Florida, I suspect some of it outside. Corrosion was evident in many places, primarily on aluminum parts.
I bought the parts back in 2019 after reading on it here. I wonder if these parts are still available.

 

[sheward]

I've gotten into the CAN components. Module terminals look fine. The diagnostic plug plastic is deteriorating, and someone has previously spliced in two new wires. It looks like they did a decent job although the two new wires are thicker gauge and then go back to proper gauge at the plug. I don't see any corrosion.

I want to inspect the wires under the plastic module terminals and resplice the two wires with the proper gauge that lead to the diagnostic plug. What is the preferred method of gaining access to the area under the colored plastic terminals? Remove the aluminum CAN case? It looks like I would then be able to unclip each colored plastic module terminal.

Also, there is one black wire remaining that leads to the other half of the diagnostic plug that is not being replaced. Normal?

 

[gsxr]

What is the preferred method of gaining access to the area under the colored plastic terminals? Remove the aluminum CAN case?

Yes. This is not fun, and the wires below are very short. Not a lot of room to work. This is the time to add the ASR defeat wiring, if your car doesn't already have it.

Also, there is one black wire remaining that leads to the other half of the diagnostic plug that is not being replaced. Normal?

The one wire to the smaller half-moon section can probably be left alone. Think it's pin #30 for the SRS diagnostic line. Most of the corrosion appears on the other/larger section of the connector.

 

[sheward]

Thank You.

 

[sheward]

I now have the Can box out and as you can see in the previous post picture there are two pins fed by larger guage wire. The 17 pin and the 4 pin.

The 17 pin returns to the smaller gauge wire going into the plug and is white in color. The other larger gauge wire combines a blue and clear wire and returns to a single smaller gauge blue wire at the plug. (4 pin) Is this all normal and factory wiring? I ask because now that I can see things clearly it all looks like it is undisturbed and bound with factory tape and something similar to a shrink wrap connection.

 

[gsxr]

Now that you mention it, yes, I believe that is factory. It may not be a larger-gauge wire, but rather a shielded wire. I recall seeing the same thing on the wires for LH and EZL on my car too. Odd it's only for those 2 modules.

 

[sheward]

I looked at your photo after I posted and I believe I see the same thing. The 2 into 1 wire had me wondering, which is why I took everything out.

Now I will turn my attention to the pins. Glad I had a look at everything.

 

[sheward]

All the pins have now been changed over to the new port.

A couple notes. As in the other examples in Daves' link to this port replacement, the number 3 pin was heavily corroded and possibly shorting to pin 2. I was able to remove it (it was the only one I had any real trouble with) by breaking away the plastic barrel on the front side and scraping the corrosion away. All the plastic on the front side of the port crumbled easily. I was able to re-use all the pins after cleaning.

Dave, your diagram in the link saved me considerable trouble. I initially pulled the yellow/white wire from location 16 as a trial, without noting where it was. I later assumed it came from location 9 above it as it is the only vacant hole in that row.

For anyone intending to remove the entire aluminum CAN housing (which makes the job easier, more so if having to solder new pins) it may be helpful to have 4 new M5 08 30mm bolts on hand. I needed to pound a larger hex bit into 2 of them in order to get them out. Steel bolts/aluminum can + 30 yrs. = corrosion.

I hope this solves my problem. I'll know tomorrow.

 

[sheward]

I've now had the car back on the road multiple times. No more CEL since the diagnostic plug replacement. I also pulled the front wheel sensors and cleaned them up. I found one small 1mm bit stuck to the right one. I mistakenly thought that I had recently cleaned these, but I was thinking of the other car. No more ABS light since the cleaning. Pump may be OK.

For anyone with an ABS light try this first. It takes about 10 minutes to do both once you get the car up off the ground.

 

[gerryvz]

Ive now had the car back on the road multiple times. No more CEL since the diagnostic plug replacement. I also pulled the front wheel sensors and cleaned them up. I found one small 1mm bit stuck to the right one. I mistakenly thought that I had recently cleaned these, but I was thinking of the other car. No more ABS light since the cleaning. Pump may be OK.

For anyone with an ABS light try this first. It takes about 10 minutes to do both once you get the car up off the ground.

Many years ago I had the same issue with an ABS light on my E500 and cleaning the front wheel sensors cured it immediately. Definitely recommended maintenance for everyone.

 

[sheward]

Small update. Thruout a 1000+ mile trip to Amelia Island the car ran perfectly. ABS light came on once more on the way out and never reappeared after restart.
I also got a CEL light again somewhere at the destination which did not clear although the car ran flawlessly while there and all the way home. So, things are not completely sorted yet. I'll post codes when I get around to pulling them.

 

[sheward]

Although I have still not pulled codes again, I've made multiple interstate trips with the car and have had zero problems. I recently was chatting with Johnathan and was reminded that a failing smog pump can light a CE light. It then occurred to me that the smog pump has always made a loud bellowing sound similar to an outboard motor when cold since I bought it. That sound disappeared sometime around when the CEL began. I believe the smog pump may be the cause of the light.

My attention has been on replacing the HVAC blower motor which I finished yesterday. I was able to find what may be the last OEM Bosch motor and install my old cages. I took the opportunity to replace the large center air intake cover and cowl drain as the original had a hole which had been patched by me during previous wiper service. I also replaced the missing foam on the upper flap. This helps to seal the flap to the blower casing when the flap is raised as well as possibly insulating different air sources. I used a piece of toolbox liner and some spray adhesive. Everything working properly now.



Took the car out late yesterday after traffic into some great twistys thru the N. Georgia mountains. 88 degrees out, AC running, music playing. No annoying blower squeal. Engine temp stayed right around 100.

 

[nocfn]

Good work, it is quite satisfying when this job is completed. BTDT