Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
have i stumped you too?
nobody around here seems to have any idea
I am still waiting for the info I paid for.
The battery has 12 volt reading
There is no voltage on the numbber 2 wire at the coil
Below is a picture of the ignition coils and the connectors. I need you to check the 2 wire plug for voltage. Put one lead of your meter on one wire and the other lead on the second wire.
Ok found it
Thought you meant the # XXXXX plug wire at first
I have 12 volts at the 2 wire plug also
Ok, this might be silly... but lets recheck to make sure the spark plug wires are definitely in the right spots!
done. All the plug wires are on correctly
Ok, at the ignition switch connector check the following wires with the test light:
1)Both RED wires - battery voltage at all times
2)Brown - Bat volt in ACCY AND RUN
3)Orange - Bat volt in RUN
4)Pink - Bat volt in Run AND Start
5)Yellow - Bat Volt in Start
will bring home a test lite tomorrow evening
all i have now is a multi meter
will let you know what i find
this is the connector by the steering column inside the car right?
Checked the wires, all are correct
Red hot all positions X2
Brown hot accy and run
orange hot run only
pink hot run and start
yellow hot in start only
all read 12 volts
Ok, with the key in run I want you to check the ECM FUSE (15amp) and GAGES FUSE(10amp) for power.
Also, just to make sure... NONE of the warning light come on in the dash?
Ok at the ECM are 2 orange wires that get their power from a fusible link that connects to the battery. They are on pins W10 and W15, check them for power.
Ok, with the key on check W16 Pink/Black for power
Check the red wire at the fuel injector for power
Also check pins W12 and W13 Black/White wires for a good ground
pink/black is hot with key on
ground is good at both black/white wires
red wire at injector is dead, no power
cant find a splice like that, is it under the dashboard or the hood?
It has a carberator also not an injector so i think the engine has been swapped out
It Looks like a carb to me, Has the choke plate just like the stuff i grew up working on.
Didnt notice the other day in the dark outside, just found the red wire at the top and checked it for power, sorry.
Dark out here now again, will look more for that splice after work tomorrow.
Think I will have to start untaping the bundles to find it
Could only find one pink/ black wire today, the one at the ECM.
Will let you know what I find.
yes its blue
Guess its not a carbjust a tube with a flapper at the top sorry
Ok, good that is the throttle body. The red wire is power and should be powered with the key on. The Blue wire is ground and gets controlled by the computer. As a test, you can try splicing a fused wire from the battery + to the red wire and see if the car will start. Don't leave it like this... this is just to test.
Ok will do it tomorrow
That splice under the dash is over towards the ECM end of the dash right?
Ok! Have a good night.
Ok Tried the jumper wire, it turned on, clicked when i hooked it up any ways,
Still wouldnt start.
Benn sitting for almost 2 months, dont suppose I should try priming with some gas maybe?
What turned on and what clicked?
Could you see fuel spray from the injector when you were cranking the engine?
Couldn,t tell what clicked, sounded like it was right there by the injector.
There is no fuels spraying in the injector when i turn it over.
Have you looked for that splice yet?
With your jumper wire hooked up try putting your test light across the 2 wires at the injector and see if it will flash when you crank the engine.
Can you still hear the fuel pump run?
Yes the fuel pump still runs.
Havent found the splice yet
Will try the test at the injector and look more for the splice tomorrow,
worked late and just got in the door tonight.
Will let you know what I come up with.
Still cant find that splice, can you tell me where the wires come from so i can trace it down?
Will have to check with the test lite at the injector tomorrow after work the battery has gone dead so will have to charge it before i can check anything else.
I think I can find it now, the splice
Will check it out and mail you back tomorrow after I check the power at the injector.
there is no splice I can find.
the pink and white goes from the fuse box to a connection block and comes out the oyther side pink and black
and goes to the computer.
The little red wire, same size as the one on the injector, plugs in right next to the pink black one from the computer. It runs into a bundle of small wires and goes up behind the AC ducting.
There are 8 or 9 wires that all plug into that connection box, they all change colors from one side to the other.
Hooked up the jumper wire to the injector again and it does not flash when I turn the engine over.
from a ground to the wire ?
or the wire to the plug?
will check it tomorrow,dark and raining out now
I'll let you know
Checked the pink white wire for power
It has power when its connected, dead when unplugged.
Had to unplug the whole side of the connection block, couldnt unplug iust the pionk white one by its self.
Ok I have re checked alll the tests youve had me do so far.
I found a mistake I made on one.
You asked me to check the ecm and guage fuses for power,
I only checked for continuity.
I checked them for power today and they are both dead.
Sorry I hope I havent caused any problems.
I'll have to patch the big dent in the wall where I've been banging my head.... just kidding...
The pink wire from the ignition switch feeds these fuses. Make sure that you have power at the pink wire at the ignition switch with the key in run. Then if so, make sure the fuses are still good, one of them could have blown when we hooked up the jumper wire.
If all that is good then we are down to a problem with the pink wire from the ignition switch going to the fuse box. You can make a 20amp fused jumper wire from the ignition switch to the fuse box to bypass the wire in the vehicle as a temporary test. You should be able to just poke the wire in from the back of the connectors so you don't have to cut anything. Be sure all other wires and connectors are connected and then try to start the car.
where do I connect the wire to the fuse box?
The ECM fuse or the guage fuse?
Found a wire we left unplugged, plugged it back in, the fuses have power again now
the jumper didnt help, still wont start
Found out whats clicking when I run the jumper from battery to injector,
There are 2 relays on the firewall on the passenger side under the hood
Its the one towards the drive side
1) Can you tell me the wiring colors on both relays... especially the one that clicks?
2) Does the relay only click one time?
3) I'm not sure if I asked you this yet... with the jumper wire installed, do the dash lights work?
Ok here goes
with and without the jumper the volt lite and oil lite only come, no change
the relay that clicks only clicks once, it has gray, black/white, orange black, and green wires.
the other relays has orange/ white, green/white, green, and blue wires, it does not click
Ok, gonna look at the schematics.... brb
While I'm doing that I want you to jumper pin #23 at the ECM (Brown/White) wire to check if the service engine soon light comes on. Leave your red wire jumpered for now too.
I meant pin 22 above.... black connector pin 22 brown/white wire.
Ok, the relay that is clicking is the fuel pump relay.
Can you put the old computer back in and see if that makes any difference with the warning lights or power to the wire at the injector?
had to turn it in for a core charge, it was exactly the same before i changed the computer
first time you mentioned that one
where is pin 22?
i will try that next
cel did not come on
Ok, connector C210 is behind the passenger side of the instrument panel. The power wire for the injector and the ground wire for the check engine light run through this connector. Right now I don't have any info as to how many wires are in it and what colors but I will search for more info in the schematics on that.
You should at least have:
Ya got it
Yes I can Do That it clips to the under dash so its accessible
Just those 4 wires or all of them?
Key on or off?
Just those 4.... both sides of the connector. All other wires plugged in, no jumpers installed.
Key in start position
Will let you know tomorrow
ok here goes
Checked the 4 wires across connector. none had any power in any position.
Hope its the right connector a couple of the wires changed colors at connector.
The pink/black changed to pink/white and and the brown/white chaned to gray
the black/white and orange did not change.
I only turned it over 2 cranks on each wire and it killed the battery, not even enough juice left to beep the key alarm.
had it on the charger all day was fresh and full
sounds like maybe a short someplace??????
The pink/black goes to pink/white
the brown/white should remain brown/white
white/black and orange also stay the same.
Something is really odd here! I need you to check the ECM and GAGES fuses again for power. These fuses power up these wires and we need to be certain there is power..... check with key in run and key in start position.
ok but will have to charge the battery again tomorrow and check afyer work
its completely dead
I dont know whats goin on now
Had the battery on the charger alll day and its still dead, didnt take a charge at all
so couldnt check those fuses
Sorry ran out of money, fridays payday and i'll get those readings sat. morn
have to get new batt cables and maybe a batt. but i'll be beack on it this weekend.
Was wodering if I need the steering wheel installed to check all this stuff.
Let me know
got the battery battery back in
checked the ecm and gauge fuses again
had power at the wires on the back of each but no reading across the front of the fuses checked the back from the wire to ground
The ecm fuse is pint white
the guages fuse is pink black
there is only one wire on each fuse
i checked the voltage from the wire to a good ground
from the front no voltage
guess thats why, only one wire
Ok, when you were checking from the front, you should leave the fuse in place and just probe the legs of the fuse. Now i assume you measured power at the back with the fuse installed with the key in run.
If that is correct then the power feed to the fuses is good, the fuses are good and the fuse box is good. (Just thinking out loud here....)
On the brake pedal is a switch. There are 2 wires... pink/black and purple. Check both of these for power with the key in run.
Also, use a test light for all of these tests including the fuses you just checked. You may get a reading of battery voltage but it might not be enough amps to make the circuit work. If you measure battery voltage with a meter but the test light does not light, then we have a low current flow which we will need to solve. Let me know what you measure.
with the test lite on the front of the fuses they have power, test lite lit up brite
The pink/ black and purple wires at the brake pedal both have power lit up the test lite brite.
With my volt meter both fuses and both wires read 8 volts.
All above done with key in run.
Forgot to tell you, I had the battery checked and they told me it read 12 volts on the high end, but the low end cranking volts were low
They said try and charge it again, it might recover.
Dont know if that has anything to do with whats goin on, thought it may be helpful tho
Ok, on the back of the cluster is a pink/black wire which is the power feed to the check engine light. Check this for power and make sure you use a known good ground. If it lights up then check using the brown/white wire as a ground. Do these tests with the key in run.
Also, check the red injector wire again with the test light and meter.
Check the battery voltage too, if the fuses read 8V then the battery is probably getting low again.
The instrument cluster where the check engine light is located.
The red wire at the injector had pwer with both the test lite and the meter. the meter read 10 volts here.
Do I have to take dash board out to check the pink/wire?
I found it I think, the pink black from the brake pedal splices into it and then it runs right up behind the cluster, but cant get the back of the cluster.
When we started all this there was no voltage at the injector wire?
By any chance does the service engine soon light work now?
Have you tried to start it?
thats correct there was no power at the injector before
no the check engine lite still doesnt come on
just tried to start it, no good,
Arggh! Have you accessed the back of the cluster yet? I'd really like to check the wire all the way at the end of the circuit.
I'm still trying to figure out how we now magically have power at the injector wire!
Havent got the dash out yet
Looks like theres about 5 screws on the bottom of the cluster part of the dash
If I remove those screws will it lift out so I can get at the wires?
Hmmm, I didn't realize how involved it was. You need to remove the trim plate, then the trim pad and then the cluster. Let's try something else.
When you replaced the ECM, did you swap your PROM out of the old one?
Thats the black plug in unit in back right?
It's the chip looking thing that plugs in under the cover.
Check for power on that orange wire at the connector with your light and meter.
Also check pins 10 and 15 for power at the ECM (both orange wires).
All three wires have pwer
Checked with lite and meter, all 3 lit up
Wire at connector read 11 volts
pins 10 & 15 both read 10 volts
Ya it is
Give me an old chevy and i can make them run forever
This new computer stuff baffles me
pink/black at ecm pin 16 key off dead
key on lites test lite, 9 volts on meter
Pink/black at ignition under hood no pwer key on or off with test lite, couldnt get at with meter
Ok, now make sure you still have good battery voltage and it's not going dead again!
Go to the ignition switch. Ground the Dark Green wire (bulb test) and see if the temp light comes on.
Also, with the key in run check all wires and tell me which colors have voltage and how much voltage.
battery still good, 10+volts
There are 8 wires on the switch
The only green is a double green, grouned with key off did not lite up temp lite
With key on:
Have power with test lite and read 9 volts, green, tan/wht, orange, 2 reds, pink and brown.
Yellow did not lite test lite and read 0 volts
Ok, the double green should get grounded with the key in the bulb test or start mode. Turn the key to run and then ground the double green wire with a fused jumper wire. The temp light should come on then. It will also come on with the key in run and grounding the gree/white wire at the coolant temp sensor. If we can verify that the temp light comes on then we will know that we also have power to the CEL since they are on the same wire going to the instrument cluster.
Also, I am a little concerned that the battery is only registering 10V and the switch is only 9V. I would expect the battery voltage to be closer to 12 and the switch voltage to be very close to 12 also!
checked the double green and the green/white
they both lit up the temp lite
cel did not lite up
checked with key of and in run, no cel
Ok, so that has to be a wiring problem or a bulb problem. Do you know for certain that the CEL bulb worked before?
With the key in run check C2 pin1 blue wire at ECM for voltage. Then unplug the injector and check again.
ok, with the key in run C2-1, blue wire has power with injector plugged in
no power with it unplugged
I am not sure if the CEL was working on not, I think it was, but my son who drives it says it never came on at all
Ok, It now seems that we have power everywhere we are supposed to BUT the ignition module. So run your jumper wire from the battery positive to the pink/black wire at the ignition module. You will have to splice it into the wire for now and leave the connector plugged into the ignition module. After you do this:
1) Try to start
2) Watch fuel injector for fuel pulsing out of it
3) If no fuel then disconnect injector and use the test light with the clip on one wire and the probe on the other. Look for the light to blink when cranking the engine.
4) Check for spark using a spark tester or a screwdriver if you don't have the tester.
Let me know if you need clarification on any of this.
5) If you have spark but no fuel injector pulse then try spraying a little ether into the throttle body and see if it will try to start.
spliced in the jumper
Still no start
No fuel coming out of injector
Test lite did not blink, no pulse
#1 plugs are soaked with oil
#3 plugs are completely dry
I'm out of town for a few days with limited access to a computer. I'll have to catch up with you when I come back.
For now, remove the ignition control module. The crank sensor is mounted to the bottom of it. Remove the crank sensor and clean the connections between the sensor and module. Also take an ohm reading of the crank sensor with your meter (if it has that function)
have been down with the flu for a week now
trying to figure out which bolts to remove to get the coill assy out so i can get to the crank sensor
can you send me a diagram or tell which ones?
theres a 1/2" bolt top and nut on stud bottom on the drivers side edge looks like it takes off the wholesection down to the block
and a half dozen or so 5/16 screws and nuts around the coil and wire connectors
not sure where to start
Sorry to hear you were sick! Hope you are feeling better now. Leave the nuts in place they hold the coils to the module. I think there are only 2 bolts next to the coil towers that remove the whole assembly from the car. You can see the holes in the picture below.
Yep am good to go again now thanks
will get after it again tomorrow after work
Thats the 2 1/2 ones, pretty easy access with the plug wires out the way
Got the bolts off the coil pack
Whats the trick to gett it off the engine?
Do I need to pry it loose?
Isnt budging at all
ok will try tomorrow
Ok, have sprayed it and let it soak over night twice and still cant budge it.
Dont know what else to do
Bout ready to scrap it and start over
Ok...... hook everything back up. Remove any jumper wires. Make sure everything is completely stock. I found a great chart for the PCM connectors. I want you to check each wire and compare to the data in the key on column. Don't worry about the engine run column.....welll... because it won't run yet!
Where is the 24 pin connector?
Yes, it's the computer.
The wires that should measure voltage you check with wire to ground with key on.
The wires that should measure ground you check with wire to power with key on
so where to i get power to check the ground wires?
all the way to the battery?
The battery is the best spot!
Also be sure to test battery voltage first. We will need this as a baseline reading. It should be close to 12V.
The leads on my meter arent long enough to go all the way from the computer to the battery
Anyplace inside the car I can use?
The best thing to do is make a jumper wire connected from the battery to your meter lead. This will give the most reliable measurements.
ok some of the wires are different colors than on that char i willl list all wires and colors and what they read for the tests.
White Plug:1 blue8+v ,2 drk grn/wht 0v, 3 red 0v, 4 gry/blk 0v, 5light blu orng 8+v, 6wht 0v, 7lhgt blu/wht 2v, 8lght drn/blk8+v, 9lght grn/wht 2v, 10orng 8+v, 11gry 6v, 12blk/wht 0v, 13blk/wht 0v, 14blk/tan 0v, 15orng 8+v, 16pnk/blk 8+v, 17lght blu/blk8+v,18orng/blk 0v, 19blk/tan 0v , 20gry 0v,21drk blu 0v, drk grn/red 6v, 23 no wire, 24drk grn0v
Black Plug:1orng 4.5v, 2prpl.33v, 3blu 3v, 4 no wire, 5tan/yllw 1.5v, 6prpl 0v, 7tan/blk 0v, 8yllw 3.5v, 8prpl 0v, 10grn 3v, 11drk blu/wht 3.5v, 12blk 3v, 13yllw/blk 0v, 14drk brwn 0v, 15 wht/blk 0v, 16blk/red 0v, 17 0v, 18no wire, 19 drk blu .6v, 20 lght grn 5v, 21drk grn /wht 8+v, 22brwn/wht 0v, 23 tan 0v, 24lght blu/blk 0v.
That is all the wires on the back of the computer and there voltages.
Forgot to tell you the battery voltage
With my little meter it read 10.5 volts
All the wiers above that say 8+ volyts also read 10.5 volts
Ok, I compared all of the voltages to the chart and there are a couple of weird ones that don't look right!
I'd like you to recheck the black connector:
Then unplug the coolant temp sensor ONLY and recheck those pins
Then unplug the throttle position sensor ONLY and rechech those pins
So you should have 3 sets of voltages to report back with. I'm particullary concerned with the ALDL Diag pin showing ground instead of 5V and the coolant/tps ground showing voltage instead of ground. I'm wondering if there is a shorted wire...
The tps is on the throttle body. It is on the opposite side that the throttle cable connects to. This sensor measures how far open the throttle plate is.
with every thing plugged in
pin3 dark blue wire, 3 volts
Pin8,yellow wire, 1 volt
pin 12, blk wire, 0 volts
pin 15, blk wht wire, 4 volts
With coolant sensor unplugged
pin 3, 3 volts
pin 12, 0 volts
pin 15, 2 volts
With throttle pos sensor unplugged
pin 8, 1 volt
pin 12, o volts
pin 15, 0 volts
these are with my meter set on 50 volt setting
with the meter on the 10 volt setting pin 3 pegs the meter, 10 plus volts
Is this a digital or analog meter?
The first set of measurements is different this time around.
Also,I 'm not sure why the meter would read 10+V on one setting but only 3V on the other??
its a cheap little analog meter i picked up for these tests
didnt make any sense to me either that it read diferent when i changed the setting
dont know whats going on, every time you have me recheck something ita always different from the last time
Ok, I wonder if it's time to ditch the analog meter and get one of these:
I'm getting worried about the constantly changing results and wonder if we are chasing our tails because of this....
will keep you in mind if i ever run into another chevy problem