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CEL on and no code
I got the CEL on but cannot get codes
Few days ago, doing nothing, the CEL turned off; I was got a code (34 MAF sensor)
Run for about 20 minutes, then the CEL turned on again, cannot get codes anymore (and engine running bad again too)
Question: why can I get any code while the CEL is on? would it be the ECU, a bad ground?
I disconnected the MAF, should be running good but still not - got another MAF, still running bad - so I suspect the ECU is in a bad loop or something (visual inspection of the ECU: perfect, nothing bad, like new)

Sidekick 92, 4dr, 16v, 5 sp - +200,000KM
ok , is this a USA federal side kick, or california or canada?
all federal sidekicks have the NAG switch, i remove all mine, they are a pita. if something serious happens. a distraction big time.
the maf unplugged dumps all ECU to LIMPHOME mode, that is really bad, runs rich , and retarded timing and burns up a good CAT as a side show. or melts it. a worse side show.

the hood sticker, is first on all USA cars, open hood, see that white EPA sticker there, vacuum map and spark plug gaps and etc.
that has Compliance text at the bottom see that, are the words California there? if NOT it is a FEDERAL car if car was bought here.
all feds, have the neg, unless i get my nasty mits on it.

this is first.
if the CEL fails to falsh, nag fixed, stuck out?
is BACKUP MODE, fred flintstone DOA, mode.
horrid rich. and retarded, think of a 5 dollar ECU home made, and bingo.

[Image: cal-tag2.jpg]

6 pin DLC, see jumper wire.

see mpi nag switch photo here.


i have all locations documented.

i unplug the NAG here

once that is out, we can concentrate on the ECU.
and ecu, that will not blink, is always a sick ecu.
assumes lamp glows, key on, no start.
it's from canada, 16v, 1992, over 200,000 km
no nag switch: looks over and over - nothing, guess someone follow your advise before (bought it second hand in 97) and remove it!
CEL glows but when it is on and engine does not run good, does not give any code when jumping (flash once when I turn engine on (not starting) and stay on)
I reset the computer (disconnect battery for few minutes): everything back normal, got code 12 (alright) - then drive for 20 minutes then back to trouble: CEL on, engine running bad and ... no code
as said before, before I let it sit for a while, came back without removing battery then CEL was off and then I got code 34.
so i suspected faulty MAF but before investing in a new one (tube one so about 250$ - ??), I want to make sure and the fact i cannot get code when cel is on looks strange to me.
i read we can run without the MAF if TPS is ok but when I reset everything and try to start engine without the MAF, I got the CEL right away and truck does not want to start at all. TPS would be faulty too??
what do you mean by: is BACKUP MODE, fred flintstone DOA, mode ?
thanks again (my sidekick is now use by my 18 y.o. son, that car has been my family car for so long - perfect car: I did not invest more than a thousand over the last 15 years more in it - so good (and no rust at all - almost like new! / except broken windshield - I need to save it!!! Smile )
yes, canada cars, have 4 flavor, back when, (changed in 1998)
1: real Canada cars, real USA, cars, and gray market. only that hood sticker shows what the truth is, of what it really easy (market wise, and what parts fit car) NO REAL CANADA CAR ever has a nAG switch ,its only cars subject to USA EPA LAWS< period. the sticker tells what you have, read it, it wont lie.

34 DTC, is a dead maf. totally dead. (or as always, bad wire to it,)
this puts the ECU in to limphome, mode every time 34s happen (rich as pig (guessing air ) retarded timing, limited RPM and no idle controls)

when you key on the ECU runs simple self checks, and the glows the CEL this means , (Im alive)
then with the jumper in place the ECu then flashes code 12s this means all tests passed, including the MAF. is ok.
code 12 means a sensors are not shorted, nor open, it passes the boot up catastrophic checks.
yours dont. if the lamp dont pass 12s that means the ECU is bad.
#1 reason the caps are bad. all ECU fail for this 1 time up to end of 1995
#1a, same but the acid that leaked from the CAPS did horrible damage to ECU main board.
for get the maf for now. never trust any ECU that is MALFing, its not tell in the truth. so , do not replace parts (sensors) until the ECU starts working.
pulling the MAF only invites, instant flooding, its not really a valid test. (yes, the MAF mimic uses the TPS angles, RPM to guess air flow, it really bad, it only for emergancy use)
Limphome is for emergancy usage, only, see. its not a driving mode, its for getting out of trouble at wits end. thing, say stuck in snon, life or death issues.

Normal ECU operations is indicated by code 12s on demand.
Limphome is with codes 13 and higher flashing.
backup mode, is the ECU is dead, that is right the ECU can inject, in this mode, its gross crude, extreme limphome suzuki calls it BACKUP. the CEL will be dead in some way is the only obvious sign besides flooding.
all that is here

all that matters is the ECU is sick, nothing else. one can not get intelligent calculations from any computer that is sick, no can do. it DEAD.
in fact this is at the top of the list off all suzuki FSM, diagnostic tables. is the CEL glowing key on, (no fix that) yes, , and is it flashing 12, No, fix that first. do not proceed.

all cars 1987 to now. all OBD cars. made on earth. up to 1996 , you must use a scan tool to see the codes. starting in 1996, no codes, is good. no more 12s starting in 1996 ,usa, and 1998 Canada cars .

this is easy problem ecu is bad.

replace cap C103 first. and look for damage (Acid spill) below it.
[Image: ECU-16v-92w.JPG]

black and white.

it is strange, the ECU must always flash codes ON DEMAND
IT must or the ECU ,is BAD,
1: key on,
2: CEL glows, (if not bulb bad, or ECU bad, or fuse blown to ECU , 3 fuses, it has, IGcoil, FI and dome, first 2 are critical fuses.
3: insert diagnostic jumper (remove nag switch first in USA FED cars)
4: the CEL must flash, if not?, the ECU is TOAST (or the Diag DLC wires are cut,,, but id bet not)
end story.

we have 1000s of post for this, in forums. it not something new, all 89/ to 1995 do this, 1 time, once fixed right per my page, it never happens again, or for 20 more years, easy.

i sure wish i knew what was on that hood sticker, sure do. (US EPA, it says ,or Canada?)
this is the first thing i do, on call cars, see what i have, then look at engine, still stock, then wiring, hacked?
non of this i can do here, im blind.

here is a canada engine bay set of tags. note the extreme difference to USA cars.
totally unique, as one would expect from totally sovereign nation.


see that oak leaf
see those words, applicable CANADA federal, motor veh, safety, bla bla, (bingo , canada real car, and parts.) and its OWN ECU.

add your hood sticker to our gallery, would love to have it, nobody but one now, has.
I found another MAF sensor: I tried it but still doing the same even if it seems to run a bit better (I remove the air box to save time switching the sensors: with my original one, passing my hand in front of the intake/sensor had the engine to almost stall, which does not happen with the borrowed sensor)
ECU looks good, no visual damage, but I will try tonight or this week-end with another one I found
ECU does not seem dead but the fact that that it does not give code when CEL is on is very strange strange
I'll get pictures too - it is a Canada model, I have the maple leaf sticker (it's not a oak) - and put them on my gallery
more to come later on tonight or tomorrow
thanks for the help,
the maf test on my web page shows how to test the MAF with a $10 DMM or voltmeter, it super easy to do... no guessing at all... see that?>
type maf in my search box. and bingo.

passing hand, you mean you attempted to hold hand over and blocking all incoming air to the engine, that is wild idea, and can hurt your hand, sucking that hard on ones hand is not a good idea.
not at ALL. ever.
barrowed sensors? what sensors?

the ecu will only be DEAD with blown fuses.
the ECU never goes DEAD, it can in fact run in 3 mode, think of it as 3 ECUs. IT IS.
Limphome, (suzuki fails safe it is offically called)
3 modes. all 3 run, but only one gets 30 MPG the the other 2 get 10mpg. or worse. that is how all OBD1 ECU work, on all cars this era.
that is right it is strange and I told you why, the ECU is in fact bad.
no ECU is good if it cant flash codes at ANY TIME>. period (nag missing) that is a fact and must pass the key glows test.

the ecu failing to flash means , the ecu is in BACKUP mode, or simply CRASHED, (lost the "NORMAL " software code is not RUNNING NOW, because IM DEAD !!!)

nice of you to add the photos. we have no photos of canada stickers (one for 98, first canada oBD2 car)

good there is no nag, there are non usa countries with NAG features, its a USA EPA brain child, only, and is USELESS to progress. for sure with flakey ECU in USA.

testing the engine or sensors is not of any USE on a dead ECU.
dead is BACKUP mode.
dead means the ECU is not using SENSORS to inject , not at all. it is only using maybe just 2, the TPS and RPM. or just RPM. see???????
BTW, SUZUKI does NOT SPEC out this mode, they give like 1 line of data. seen here.

a double dead ECU will not start, say all 4 injectors drivers died.
or the main regulator in the ECU died, killiing all injectors and all spark dead. double and triple dead.

the ECU is just a computer
if you study them most say, Backup mode is used when the main processor dies. (or lost 5v) and switches to a BACKUP chip
imagine a chip that can only inject, fixed rates of injection and fixed spark
I consider backup mode to be like your lawn mower, just enough parts to mow lawn, waste fuel and make black smoke, as the surely are.

this is how all ECu work.

3 modes, yours is in backup mode. DEAD< dead means, its in lawn mower mode.
this mode can save your life, that is ITS ONLY feature.
if you had custom ECU, the engine would be dead, because 99% off all custom ECU dont have backup or limphome. so on custom cars the ENGINE STALLS.

guess how i now that. well I own 2 cars with that. I programmed both and turned them.

when my CEL dies, (will not flash on command, and is stuck off or on all the time) no flashing means IM DEAD, (backup mode if starts engine)
i get a new ECU.
most come back to life with a new C103 , many are split open others are dry inside. and read zero.
i remove it and connect it to my ESR /Cap meter, omg , it's 0 micro-Farad's it's just an empty dry shell inside. this is very common, on Rubicons, and never happens 1996+ (fact)

i do not try to test sensors with a dead ecu.
that be like asking a monkey to do calculus.?

its not strange, its BROKEN, seen many. too many

get a rebuilt ECU,'
I use, Cardone, they are #1 .
but many ecu CAN BE GOOD USED, If YOU CAN FIND THEM with the RUBIcon replaced.....
all RUBYs fail. all. (original still)

my ECU dead page covers all that , and all the way s and means to solve that.
even a bad injector is covered and how to fix any ECU output that is DEAD.
its all there.

The ECU that can NOT be fixed (DIY) is the ones that have acid damage.
this damage can be very very bad,
and hard to fix. I can but is hard.

never use bad logic (bad ecu ) to test sensors, it just a waste of you time,.. i promise.

point 2
putting any hand near a working mAF (ecu not bad) will cause huge turbulence to the maf hot wire, making it go nuts.
why do that. ?
its a very fragile and $1000 air meter, in fact the engineer did all he could do to get the air flowing past it to be STRAIGHT. and laminar.

some MPI maf have screen in front of the MAF, this is NO SCREEN, it is in fact a Laminar adjusting device. it makes the air go STRAIGHT.
do not mess with these parts. with hands or upset it. It proves nothing. and is risky to the very expensive mAF, .

better , ? use my maf page and any dirty cheap volt meter ever made. any Vmeter works. here
here is the page

see fast rule test here. all this is very very simple testing of the maf. (even a dirt cheap flow bench)


some of my tests, are on EXPENDABLE MAFs, to prove dynamic range only. (im showing how high i can get the output with no engine,)
In a real car, you just drive and watch the scan tool and MAF on display,
like this

point 3
the ECU can not tell you if a MAF is weak, only DEAD, or stuck high.

what you experience is low power wide open throttle.
finally I got time this week to work on it
I replaced ECU and MAF with tested ones: both good; problem is not there

engine goes good couple minutes, then CEL turn on : 34
engine runs so-so, if I open throttle slowly it will go in high RPM but if I hit the gas pedal fast or let it go too fast, engine wants to stall
code 34 is telling that there is a problem with the air intake and symptoms confirm this but what can it be?
there are many hoses, valves, sensors all around the injection: can it be that? but no idea what they are all about!!!

and finally, here is a picture of the Canadian tag, with the maple leaf
[Image: 411_13_09_14_11_38_10.jpeg]

I hope to find soon! really miss driving it!! Smile thanks
|Sidekick 92, 4 dr, 5sp, 16v, over 200,000KM, Canada
OMG, nice photo THANKS!!! very much, love non uSA tags !! a real market 28 car, great and early too...

finally I got time this week to work on it
I replaced ECU and MAF with tested ones: both good; problem is not there (must mean DEAD CEL GONE??????)
but WHAT about the DEAL CEL DEAL??????

engine goes good couple minutes, then CEL turn on : 34 (the ECU never lies about 34s they are real)
keep in mind 34s means ecu is in limphome mode. fact. all running effects are of no matter, (all limphome modes run bad, all)
the 34 means the MAF is DEAD, as a door nail, and most used MAFS are dead and most CHINA cloned MAFS same (see my hacker page for why)

the below is of no importance, LIMPHOME IS WELL Limphome (suzuki fails safe)
its like trying to fix a leaky kitchen faucet and the tornado blew roof off last night, the sink is to be ignored.
engine runs so-so, if I open throttle slowly it will go in high RPM but if I hit the gas pedal fast or let it go too fast, engine wants to stall
code 34 is telling that there is a problem with the air intake and symptoms confirm this but what can it be?
there are many hoses, valves, sensors all around the injection: can it be that? but no idea what they are all about!!!

and finally, here is a picture of the Canadian tag, with the maple leaf

Progress. no more dead ECU.
ok so why do you think there are good used MAF's in the wild,. after 22 years?

the maf outputs voltage to the ECU , across a precision 1000 ohms resistor. (see my maf page for how that works)
so the ECU sees lower that 0.65 mA. that is 0.00065 amps,
V= I times R.
so .00065 amps times 1000 is 0.65 volts. (E= IxR or in gringo, Voltage equals , current times resistance.)
or 1000 times .65E-3 (sci notation) = 0.65v.
this reading never lies. the ecu will not fib here.

only why remains.?
at idle the voltage is [color=#FF0000]1.7

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