to all the mechanics out there i need some help

basically i have been having a tempramental problem with my car... its an auto and say if im driving along and i take my foot off the accelerator pedal and then go to put it back on its like the car lags, it drops around 500rpm and then kicks in, asif it goes to stall and then fires and goes.... it basically happens whenever i take my foot off the accelerator pedal and go to put it back on, so if i already have it on and just push harder it doesnt do it at all

as i said this is only something that just happens when it decides to.... when it does happen, if i turn my car off i cant seem to start it, it will eventually start but after like 10-20 minutes or so.... i thought it could be the spark plugs and my car had stopped while parked out the front of supa cheap auto so i went and bought some new ones and when i changed the old ones they were black as black.

so with them changed over the car seems to be running fine but like i said its a tempramental problem and could come back (ill let you know if it happens again)...

now the question i wanted to ask was why would the ECM or engine light be coming on and off??... everyone i have talked to said basically it could be anything, take it to a mechanic, but... being that i work with my hands and want to save some money id rather check a few things out first (although im no mechanic)...

so can anyone give me a short list of things to check on my car to see if i can get the engine light to turn off.... i know its not good but i dont know for what reason????

sorry for the long post but anyone help would be greatly appreciated


cheers


skitzo

checked vitals such as oil levels etc?

Also did you correctly gap the spark plugs?

Easiest way to find out would be to connect a scan tool and read the code. Black plugs usually means it's running way rich. What sort of car is it?

car?

If it's a VR/VS then likely to be the crank position sensor. You can read the diagnostic codes easily on these cars (without a computer). Let me know if it is, and I'll send you the diagnostic data sheets.

or it may be the alternator 'surging' causing the computer to glitch.

yeah mate it is a VR, i wouldnt have a clue what it is but i was speaking to my g/f's dad tonight and he reckons it could be similar to what your saying now..... if you could send me them and tell me basically what to do would be awesome man.... i dont really have any idea on what to do with the sheets or how to read any of the info


cheers



skitzo

Diagnostic instructions
Click to view attachment
Click to view attachment

Codes overview
Click to view attachment

There's a separate section for each error code....

hey champ, some reason those pdf's dont seem to be loading, is this happening with other people or only with me??


cheers


skitzo

Try this. http://www.techedge.com.au/vehicle/aldl160/vn_aldl.htm

so basically i is it that i have to go and buy one of these ALDL connectors, and read what signals it gives me and that will tell me where the car is picking up an error??

how much are one of these going to cost roughly and what sort of shops would i be able to get one from??

hopefully when i buy one and take the car apart i will be able to find out the rest myself


cheers



skitzo

Stolen from Just Commodore forum. Originally posted by Darren, Site Administrator

Locate the diagnostic connector under the the steering column on the drivers side.
Grab a paper clip and bridge pins number 5 & 6 'black' and 'white with black stripes' respectively on the ALDL (Assembly Line Diagnostic Link) connected which are located on the top row counting from the left.
Turn the ignition key to on (so lights are up on the instrument cluster).
If you bridged out the correct wires 'Check Engine Lamp' will be flashing.
The flashes are divided into 2 groups with roughly a second between each. You can read the flashes as follows:

The first series of flashes is tens, so for example lets say the first flash simply flashes once, this means the code is 10. After the pause (~1 second) a second series of flashes will appear, if this number is 2, the code it is spitting out is 12 which means everything is fine.

Another example just so you're sure

The first series of flashes you count is 4 meaning 40, the second series of flashes is 3. Adding the 40 and the 3 will give you a code of 43 which means the Knock sensor circuit is experiencing problems.

Each code the computer picks up is repeated three times with ~3 second pause between, so its wise to sit there to make sure there isn't any problems it has picked up.
Once you are finished turn off your ignition and remove the paper clip. It is important to note not to drive the car around while have wires are bridged as this will prevent new codes from being logged.




Link for codes

yeh, that's it, I'll post up the codes in text...

SECTION 6C1-2A
DIAGNOSTIC CHARTS - V6 ENGINE

DTC 13 V6 PCM - Right Hand (RH) No Oxygen Sensor Signal
DTC 14 V6 PCM - Engine Coolant Temperature (ECT) (Signal Voltage Low)
DTC 15 V6 PCM - Engine Coolant Temperature (ECT) (Signal Voltage High)
DTC 16 V6 PCM - Engine Coolant Temperature (ECT) (Signal Voltage Unstable)0
DTC 17 V6 PCM - PCM Error - ECT Circuit
DTC 19 V6 PCM - Throttle Position (TP) Sensor Stuck
DTC 21 V6 PCM - Throttle Position (TP) (Signal Voltage High)
DTC 22 V6 PCM - Throttle Position (TP) (Signal Voltage Low)
DTC 23 V6 PCM - Intake Air Temperature (IAT) (Signal Voltage High)
DTC 24 V6 PCM - No Vehicle Speed Signal (Automatic Transmission)
DTC 25 V6 PCM - Intake Air Temperature (IAT) (Signal Voltage Low)
DTC 26 V6 PCM - Intake Air Temperature (IAT) (Signal Voltage Unstable)
DTC 28 V6 PCM - Transmission Fluid Pressure Switch Assembly (PSA) Circuit Fault
DTC 31 V6 PCM - Theft Deterrent Signal Missing
DTC 32 V6 PCM - Mass Air Flow (MAF) Out of Range
DTC 35 V6 PCM - Idle Speed Error
DTC 41 V6 PCM - Ignition Electronic Spark Timing (EST) Output Circuit Fault
DTC 42 V6 PCM - Ignition Bypass Circuit Fault
DTC 43 V6 PCM - Knock Sensor Circuit Fault
DTC 44 V6 PCM - Right Hand (RH) Lean Exhaust Indication
DTC 45 V6 PCM - Right Hand (RH) Rich Exhaust Indication
DTC 46 V6 PCM - No Reference Pulses While Cranking
DTC 47 V6 PCM - 18X Reference Signal Missing
DTC 48 V6 PCM - Camshaft Position Signal Missing
DTC 49 V6 PCM - Cam/Crank Signal Intermittent
DTC 51 V6 PCM - PROM Error
DTC 52 V6 PCM - System Voltage Too High - Long Time
DTC 53 V6 PCM - System Voltage Too High
DTC 54 V6 PCM - System Voltage Unstable
DTC 55 V6 PCM - PROM - Analog - Digital (A/D) Conversion ErrorA-154
DTC 57 V6 PCM - Injector Voltage Monitor Fault
DTC 58 V6 PCM - Transmission Fluid Temperature (TFT) (Signal Voltage Low)
DTC 59 V6 PCM - Transmission Fluid Temperature (TFT) (Signal Voltage High)
DTC 63 V6 PCM - Left Hand (LH) NO Oxygen Sensor Signal
DTC 64 V6 PCM - Left Hand (LH) Lean Exhaust Indication
DTC 65 V6 PCM - Left Hand (LH) Rich Exhaust Indication
DTC 66 V6 PCM - 3-2 Control Solenoid Circuit
DTC 67 V6 PCM - Torque Converter Clutch "ONOFF" Circuit Fault
DTC 69 V6 PCM - Torque Converter Clutch Stuck "ON"
DTC 72 V6 PCM - Vehicle Speed Signal Intermittent
DTC 73 V6 PCM - Pressure Control Solenoid Current (Current Error)
DTC 75 V6 PCM - System Voltage Low
DTC 76 V6 PCM - Short Term Fuel Trim (STFT) Delta High
DTC 78 V6 PCM - Long Term Fuel Trim (LTFT) Delta High
DTC 79 V6 PCM - Transmission Fluid Temperature (TFT) Too High
DTC 81 V6 PCM - 2-3 Shift Solenoid "B" Circuit Fault
DTC 82 V6 PCM - 1-2 Shift Solenoid "A" Circuit Fault
DTC 83 V6 PCM - Torque Converter Clutch (TCC) Solenoid "PWM Circuit Fault
DTC 92 V6 PCM - Low Speed Fan No BCM Response
DTC 93 V6 PCM - SNEF Circuit Fault
DTC 94 V6 PCM - No Vehicle Speed Signal (Manual Transmission)
DTC 97 V6 PCM - Canister Purge Circuit F

alrighty then, seems reasonably straight forward to find the problem, now for the last question, where abouts do i buy one of these connectors from??


cheers



skitzo

you don't need the connector, it's already in the car.

below the steering column, just to the left a bit (on the black plastic below the fold-down flap) is the connector.

sorry bout my last post i some how missed ivantheterribles post and read on to pulse-r's post at the end, thanks alot guys

i will be back to let you know what the problem is as soon as i find out


cheers



skitzo

yep, sounds like the crank angle sensor....had similar prob with my vr a while ago. car simply wouldnt start every now and then - but may start after 10-20mins of first trying.

buy a new crank angle sensor - about $200-$300 from memory (new). is a very common prob with vp-vs commos

I wouldn't rule out the alternator - do you find the lights get brighter sometimes while driving at night?

If it is the alternator 'surging' then do not get a holden one - much better to upgrade while you have the opportunity. Apparently the VT alternators are quite good.

Holden dont make alternators. And a VT alternator wont fit a VR V6.

hey peoples, car has been in mechanics lately and apart from that has been running fine but now starting to have the same problems as before.... the error code that i got was 16 which is





DTC 16 V6 PCM - Engine Coolant Temperature (ECT) (Signal Voltage Unstable)0


now i cant understand why it says engine coolant temperature as i have just had a new radiator put in and thermostat etc, and car doesnt seem to be warming up at all....



im again having the problem where my car will go down in revs before it goes up when i put my foot on the accelerator, for example "car is cruising doing 60km/h at 2,500rpm, my foot goes from being off the accelerator to on and the rpm goes down to say 1,800rpm before it will kick in and go up??



could this be in any way related to the engine coolant temperature or the reading that i got in some other way??





cheers





skitzo

alright, i just went back out there to make sure and thought i would sit in the car for a while and just see if any other messages came up... now i got all these messages, numbers



12 which there isnt even something for on that chart

DTC 15 V6 PCM - Engine Coolant Temperature (ECT) (Signal Voltage High)
DTC 16 V6 PCM - Engine Coolant Temperature (ECT) (Signal Voltage Unstable)0
DTC 17 V6 PCM - PCM Error - ECT Circuit

DTC 31 V6 PCM - Theft Deterrent Signal Missing



now the 2 engine coolant temperature ones i just realised could have been from before i took it to the mechanics and got the problem fixed as it was just the other day and im not sure how quickly these cars keep there memory or maybe if it still is a problem, im not sure



the PCM error i have no idea about????

and the theft deterrent signla missing, obviously its something to do with the immobiliser in the car but i cant see it would make the problems that i am having with the car now



any ideas

did you change the crank angle sensor yet.

Also no engine coolant should not effect the engine idle.
But the transmissin will affect the idle or the dropping of the revs you are talking about.
Also i would try the plugs again if that fixes it again i would recomend you have a mechainc look at the coil packs and the ingtion module.


P.S I am a ford mechainc and i hate V6 commodores but i will help were i can.

lets go through this slowly...


DTC 15 V6 PCM - Engine Coolant Temperature (ECT) (Signal Voltage High)
DTC 16 V6 PCM - Engine Coolant Temperature (ECT) (Signal Voltage Unstable)0
DTC 17 V6 PCM - PCM Error - ECT Circuit

firstly, error 15/16 are both relating to *voltage* not engine coolant. It would appear that there is a problem with the wiring to/from the ECT unit.... indicated by signal voltage unstable/high.


Now, have a look at #17, what does it have in common with 15/16? the letters "ECT"..

ECT circuit, which is what i just alluded to in 15/16 as being a potential problem...

Now, im no mechanic, i dont do alot of work on cars other than my own(which doesnt have all thi fancy tech info so yeah..), im just using basic logic and deducing assumptions from the information given to me...

from my point of view(with my limited knowledge of these cars and their circuitry/mechanics, i would suggest that its something to do with the electronic circuit relating to the ECT, rather than something to do with the coolant temp, as such...

And the other one about theft, it doesnt have to be affecting performance to come up in that list. i would assume its something the service mech's check before they service the car, so they know what *is* wrong wth it.

all in all, it sounds like a problem with the cars electronics more than anything. did you get the mecanics to look at it and explain the problem to them?

perhaps speak to an auto-elec about this...

Yea good piont you make did not noticed that it was all elec problems just noticed the coolant problem and normal its a faulty coolant swicth not the wiring.

Did not read much into.

sorry mate i didnt even see the post about the crank angle sensor, yeah it doesnt start every now and then but will start after 10 minutes of giving it a go, tell you the truth i have no idea about cranks or crank angle sensors so i wouldnt even know where to start if that was the problem, i will see if there is anything else i can do, if it continues to be a problem which it usually does i will obviously save the money and get a new one put on

if you take the battery off for 5 mins, it will reset the codes, then when you put the battery back on, you have to run at (I think) 1500 RPM for a couple of minutes, then do some driving thing.... anyways, then check that the codes are cleared. If the car does that jerking thing again, re-check the codes.

It could be faulty temperature sensor wiring, which is confusing the auto. does it do the same in "power" and "economy" switch?

the immobiliser code means the immobiliser (if fitted) is not fitted in with the computer wiring, or you have no immobiliser (The factory VR/VS alarm has immobiliser built in).

im not sure about between power and economy but in 3rd when i take my foot off the accelerator the revs sort of jump up and down, say from 1,800 - 2,100 rpm and it just jumps up and down, only noticed this a minute ago... having so many troubles with this damn car lately, just at the same time im starting to get somewhere with my false floor/boot install

nah i took it to the mechanics with this problem well what i thought was this problem, they fixed it (was faulty spark plug leads) and gave it back, car ran fine and now its stuffed up again.... honestly i have so much on my mind right now that this car is getting some attention when i can but my mind didnt even click on to all three saying ECT and honestly im not sure what it is, but i will have a look in to that and ask my mate (mechanic) and see what he reckons about it

even vaccum leaks under acclractor no problem then when you back no vaccum is there and cause the jekes too so many possablety.

My $10 says its not the crank angle sensor but something in the DFI module. Why is this you ask ? I'm glad you did !

1. When the crank angle sensor goes kaput, the engine just dont run, not act erratically. Quickest way to check if its the crank angle sensor, when it starts acting funny get a 1 litre bottle of water and squirt it all over the balancer. CAS will go funny due to heat, its located near the balancer, so squirt it with water and the thing cools down... and if it IS your problem, then whatever funniness the cars doing will go away.

2. You had the leads replaced and it worked fine for a bit, then went screwy. Well, the DFI triggers the coils.. and the DFI is notorious for dying in Commodores. My tip, remove the DFI plug (the DFI is the flat heatsinked thingy under the coil packs.. the DFI plug is the wide plug on the right going into it), clean both side with CO Cleaner, and re-assemble and see what happens.

While you're at it, remove the leads on at a time and clean them out with metho on a cotton bud, and rough up the terminal with steel wool.

Have the plugs been done ? If not, get the replaced.. and check the center one on the drivers side when its out, I bet it looks pretty sickly (its the most common failure).

Check the drivers side leads for scorch marks.. they're notorious for arcing across each other.. especially the one for the center plug (I told you it was trouble ! haha)

The last two things to try..
1. Change the air cleaner element.. funny idle problems can be caused by a clogged filter. Another symptom is increased fuel consumption.
2. Take the intake pipe off and clean the throttle thoroughly with carby cleaner. Old engines always have a massive carbon deposit on the throttle, its a fact of life.. it also blocks the idle air flow and causes idle issues and doughiness off throttle.

Oh and check those ECU error codes.. codes 15, 16 & 17 all point to a crook temperature sensor OR crook temp. sense wires. Code 31 means you dont have an immobiliser connected. Code 12, dunno, I'll ask a mate and see if he knows.

I bet you're all thinking "How can he know all this ?".. I've had all these problems with the 4 Commodore's I've owned, some things are just typical of that engine and ignition design. If only they'd gotten Mazda to design their engines..

Ah yeah, check the O2 sensor too, Commodores of that vintage tend to need new ones as well.. and a sick one will randomly light the engine warning light.

DFI thats it when i said ingtion moudle thats watt i ment the thing under the coil packs.

LIKE i said i am a ford mechanic never can remember the name holden gives things.

Blackice mate works for holden if i remember rightly too.

(i guess he will ring me when the new laser turbo has problems)

I think code 12 tells you there are more codes coming... like "You are in DIAG mode" or something.

Yeah Bushman, he's the head mechanic for the Holden HSV service center here. He's also worked on a lot of my cars and hated them all



Pfft, Laser having problems.. NEVER ! Altho you can come fit my new starter motor if you like

alrighty, well i cleaned the wide black plug, (cant remember name) and put the carby cleaner through the throttle body (thats what i think it is anyway) and it was absolutely full of black crud which i knew it would be and knew it had to be cleaned so i cleaned it all out and sprayed it thoroughly and car seems to be running alot better



took it for a drive, car ran fine but the engine light came on again and i had forgot to disconnect the battery before so it would whipe the memory so i have done that now, will take it for a drive soon and see how it goes and what codes i come up with, surely its gotta be getting narrowed down now





cheers





skitzo

alrigthy well just taken the car for a drive again after taking the battery terminal off



now numbers 12, 15, 16 come up and thats it so gotten rid of 1 or 2. the spark plugs have been done about 3 weeks ago and when the mechanic changed the leads over the said they were in top nick so i cant see there being a problem there



still stuck for ideas on what to do as the car still has the same problem on re-acceleration / take off.

i think i have pretty much done everything that has been brought up apart from the new temp sensor and sensor wires but some reason im leaning towards thinking this isnt the problem although that could be the problem why the light is coming on, more interested in getting the car running right first.



could it be the coil packs at all?? after speaking to a couple of people (just friends) most have said its probably the coil packs, is this a likely possibility and if so are they easy to do??



thanks heaps for all your help fellas, greatly appreciated

coil packs are easy to change on them then sit at the top of the motor.

check the main earths also - the one from the battery to the side of the guard, and the one from the battery to the engine...

still could be the crank sensor playing up - as it may be advancing/retarding the spark too much.

As for the codes, most likely a dodgy wire from the thermosensor to the ECU.

alrighty i will re-do the ground as i have been meaning to do this anyway with the stereo upgrades of late so yeah ill re-do that for sure



also are the coil packs an expensive thing to do?? because if there not i might do them anyway





cheers

I've never had a faulty coil pack (VR), but my brother (VS) had 2 duds.

alright, well after all the problems i have had with it, its all come down to 1 thing.... it was the engine coolant temperature sensor that was buggered, while the mechanic was there he said the alternator was making lots of noise so i got that fixed too... finally its running perfectly, just in time to sell it haha



finance came through for the ute that i want so looks like ill have a different car next week or so and be in the process of taking all my stereo equipment out of the old car and seeing what i want to do with it so i can sell the old car off





cheers for all the help fellas