IO Jan 02 - intermitant Ignition problem
Regularly after driving for some minutes, the ECU light comes on and runs only on two cylinders - the front coil control becomes inactive - already replaced both coils (4G94 engine). Turning ignition OFF then ON resets problem with all four cylinders OK but problem can occur again within minutes of driving. Cannot read OBD1 codes (tool will not workon this ECU for some reason. Also idle speed appears too high at 1100rpm.
I hope someone can help!
Am I correct in saying that this model IO of Jan 02 has OBD1 (not OBDII) inteffacing to ECU?
Thankyou. I already have
Thankyou. I already have found the error codes by this method. They were 13 & 44. 13 being ïntake air temp sensor fault. 44 being the result of ingnotion coil fault on cylinders 1 & 4. The sensor is believed to be in the air flow senser assembly just after the air intake / filter chamber. Currently pursuing a replacement. Hopefully this will solve the problem!
I don't think that's it.
I can't see an IAT sensor issue causing the ECU to not drive one of the ignition coils - from what you say, it sounds like switching the ignition off & back on maybe clearing/resetting whatever fault causes the problem, and may also be clearing/resetting related codes.
Disconnect the battery to clear the codes - drive with the jumper installed, and then read the codes when it starts to misfire - before swtching off the ignition - see if you get the same results.
The IAT (Intake Air Temperature) sensor tells the ECU the temperature of the air being drawn into the engine, a failure could cause the mixture to be slightly off, which might cause a misfire, but this will affect the entire engine, not just two cylinders - also - the IAT is a "non-essential" sensor, if the ECU knows it has failed, the norm is to compensate to allow the engine to operate safely, and turn the check engine light on to alert you to the failure.
Tried reset ans drive
Very much appreciated your guidence - certainly makes sense. I re-installed "Air flow sensor" after inspection and reset error codes. With Pin 1 grounded, took it for a drive and the problem of front coil not working has not occurred again. Will take it for a longer drive tommorrow to hopefully work up confidence that the problem has been cleared (somehow!).
The idle speed is still too high at 1100rpm - inspected "Throttle actuator control motor" and all appears OK - the idle speed increases when for example the steering is moved hence stepping motor would appear to be working.
Not relaxed about not knowing why the intermittant problem of deactivation of front coil occurred. The idle speed problem that seemed to occurr at the same time may or may not be related. Any more guodence would be appreciated. Need to make it from Sydney to Broken Hill & back without problems!
idle speed too high
I am not an expert in this area but was the idling too high before you disconnected the battery ? If not, try to let the car idle by itself for 10/20 min it might adjust itself. I had something similar and it came good doing this.....
Broken Hill is great, make sure to visit Silverton as well....
Happy io
Code 44
Hello guys, I know this is a very long shot becuase this post is from almost a decade ago, but I´m having the same issue with Code 44 about the ignition coils, alredy replaced spark plugs and coil packs, but the issue remains, it used to run on only two cilinders and when i turned off and on the car, issue would go away and the car would run again fine. After changing spark plugs and coil packs the issue when away for a couple of days, but now when the engine has been running for a while I believe it misfire a bit because it looses power for a second and then it comes back but without turning the check engine light on, sometimes the tacometer goes a bit crazy and it doesn´t mark the correct revs, a few weeks ago the car died becuase the ground for the crackshaft positioning sensor came loose somehow, the mechanic fixed the issue but it died on my again a couple of days ago, a haven´t scanned it yet but I think it has to be the same isuue with the crackshaft sensor, but now I don´t know if everything is connected somehow in some way, its a 2003 with the 4g94 engine, I hope you fixed the issue in the past and can give me some guidence on how to solve this issue, thanks.
Syndicate
Ground Pin1
Locate the diagnostic connector under the dash and ground pin1 (either to the chassis or to pin4), switch the ignition on and look at the check engine light - it will flash the fault code(s), which you can then research in the manuals available in the resource section.