CEL

[PrecisionBoost]

It's a posibility that I've allready been exploring

The 6spd F28 would make a nice addition to my Optra.

I'm not sure how much power it can handle in 4wd mode.... most guys convert it to Fwd when pushing serious power levels.

[PrecisionBoost]

The modification I'm really serious about is the addition of two 40hp electric motors to each of the rear wheels.

I would have to get the rotary encoders used for ABS systems so that I could ensure traction control but it would certainly add some very serious low end torque.

In many cases a single 40hp electric motor is used to make an electric vehicle out of a VW rabbit so you can imagine what 80hp would do to a car like mine (especially if the front end is making 300whp)

An electric motor makes all it's torque down low near stall speed so it complements a gasoline engine perfectly.

[Chip]

No sir. Not correct. CEL will throw for anything from a disconnected/bad air intake temperature sensor, disconnected/bad MAP sensor, disconnected/bad oxygen sensor, and many other faults. My car (Jamaican spec Cielo 1.5 GLE) never came with a catalyst, nor does it have a knock sensor. I do have a working CEL though. The CEL will not, however tell you that a SENSOR is at fault. It will tell you if the CIRCUIT related to that sensor is at fault. Could be a bad sensor or a disconnected sensor. Either way it needs attention.

Yes, I know all the different conditions that cause the ECM to set the CEL. I work with these cars and ECMs every day and help to test the diagnostic strategy. What I'm saying is the only instance where the CEL will FLASH is when the ECM has detected catalyst or engine damaging misfire.

[PrecisionBoost]

What I'm saying is the only instance where the CEL will FLASH is when the ECM has detected catalyst or engine damaging misfire.

You seem like a smart guy and I'm sure you know what your talking about when it comes to other vehicles but I question your familiarity with Delphi and AC Delco management systems.

Again.... here is the GM Techline service manual description of a flashing CEL.....

If the control module detects a high level or catalyst damaging misfire, the control module flashes the MIL at a rate of once per second.

So your incorrect in saying that only a misfire will make it flash.... a "high level" will also make it flash..... which was the case with my vehicle.

Typically ECU sensors usually run between 0.7V to 4.5V so that the ECU can do self diagnostic tests on the sensors. ( check to make sure they are not 0V or 5V and that they are a nominal value compared to previous ignition cycles )

If the ECU sees 0V it gives solid CEL because the sensor path is an "open circuit" compared to the sensor reference voltage

If the ECU sees 5V it gives a flashing CEL because the sensor path is a "short circuit" compared to the sensor reference voltage

[Chip]

You seem like a smart guy and I'm sure you know what your talking about when it comes to other vehicles but I question your familiarity with Delphi and AC Delco management systems.

Haha...actually, these are the systems I'm most familiar with.

If the control module detects a high level or catalyst damaging misfire, the control module flashes the MIL at a rate of once per second.

Ok, I believe here that they are either using "high level" to define catalyst damaging misfire, or the "or" is supposed to be an "of". I say this because the CARB regulations (Title 13, California Code Regulations, Section 1968.2, Malfunction and Diagnostic System Requirements for 2004 and Subsequent Model-Year Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles and Engines (OBD II)) specify that there are only two conditions that a manufacturer should flash the CEL. One is catalyst damaging misfire, the other is at a "key on, engine off" situation where the ECM runs through all of the diagnostics and reports whether the systems are properly functioning or not. So, if you have ever experienced a flashing MIL for any situation other than misfire while the engine is actually on, please let me know because I should inform Delphi that they are out of compliance with the 1968.2 regulations. By the way, what service document are you looking at, because mine only mentions a flashing MIL under the P0300 DTC which is the misfire DTC code.

Typically ECU sensors usually run between 0.7V to 4.5V so that the ECU can do self diagnostic tests on the sensors. ( check to make sure they are not 0V or 5V and that they are a nominal value compared to previous ignition cycles )

If the ECU sees 0V it gives solid CEL because the sensor path is an "open circuit" compared to the sensor reference voltage

If the ECU sees 5V it gives a flashing CEL because the sensor path is a "short circuit" compared to the sensor reference voltage

Yep, this is exactly right, except that these situations won't cause the CEL to flash. My company has done all the demo testing on these ECM systems, meaning we have caused malfunctions in every diagnostic to set every CEL code and the only time it flashes is during catalyst damaging misfire, just like the regs read. I'm sorry for any confusion on this, but if your CEL is seriously flashing for any other reason I would love to see the freeze frame data.

In the meantime, Kinky, I believe your CEL may actually be blinking because your car may not have TEC learned properly. If you don't do the proper procedure, the ECM will learn on its own, but it takes 3 drive cycles of taking it easy. We just experienced this with the rally car.

[lanos2001]

but if your CEL is seriously flashing for any other reason I would love to see the freeze frame data

well my CEL is flashing about everytime i drive but after at least a few minutes of driving. not sure which system i have on my car. and the few times i went to get the code read nothing came up at all. what could that be about?

nick

[PrecisionBoost]

Haha...actually, these are the systems I'm most familiar with.

By the way, what service document are you looking at, because mine only mentions a flashing MIL under the P0300 DTC which is the misfire DTC code.

My company has done all the demo testing on these ECM systems, meaning we have caused malfunctions in every diagnostic to set every CEL code and the only time it flashes is during catalyst damaging misfire, just like the regs read.

Well... I'm not sure why it was worded like it was.... the stuff I posted was the exact information the GM ESi Techline manual was listing.... I think I assumed too much due to the fact that during the rest of the manual it uses the wording "high level" and "low level" to represent voltage levels out side of the normal operating levels.

After further investigation I would say that your 100% correct about the CEL flashing only when a P0300 DTC is encountered.

I'm more familair with Hardware than software so I must admit that this is the first time I've run into the issue of a flashing CEL

So you work with Delphi and AC Delco ECU's ???
Which other vehicles use the newer Delphi systems?
What do you do for a living??
What does your company do??

I'm in the planning stages of designing a complely new standalone engine management system... perhaps you might be a good person to talk to along the path of product development.

[PrecisionBoost]

This is the wrong place to talk about this but I just wanted to give a brief run down of the new digital engine management system I'm designing.

Basicly each sensor will have an individual microprocessor converting and evaluating analog data via an onboard A/D converter.

There will also be digitally addressable "drivers" to operate the various components such as ignition, fuel injectors, EGR valve, Idle air control.

The "sensor bus" will most likely use CAT6 network cable with a hub system so there will be very few wires.

The primary processor will request sensor data over the digital bus and the correct sensor will then respond with a digital transmission of the data it has collected.

Each microprocessor will also be able to send a "high priority" transmission back to the primary processor if it has unusual readings. (such as a misfire)

There will be an LCD user interface (possibly touch screen) which will allow the user to monitor information from any sensor as well as modify parameters for different styles of driving.

Having a parallel processing system will allow flexibility in design and increase the over all speed and performance of the system ( while keeping costs down at a reasonable level )

Anyways.... I'm sure we will talk about it later.