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View Full Version : Car Troubles, Any Mechanics/Auto elecs Here?



NedsHead
4th Nov 2018, 09:47 PM
The missus car has been giving me grief and I haven't had any success getting to the root cause.

Two weeks ago the check engine and service light came on in her TS Astra 1.8ltr ecoTec (one light, then the other) and the car lost some power to the wheels (it's now like driving with the hand brake on)

I took it to an auto electrician to retrieve the fault code and it came back with a P1985 (actual torque fault) and a P0700 (transmission control system malfunction) they cleared the codes from the ECU but it didn't last long, I got the car home but when I started it again the service light returned and so did the symptoms.

I wasn't too keen on spending another $50 at the auto elecs so I bought a $50 OBDii scan tool and retrieved/cleared the codes myself, this time the code was a P0100 (MAF sensor or circuit) and a pending P0700 (transmission control system MIL request) I cleaned the MAF, cleared the codes and the car drove fine for about half a day

The service light came back on and the car has lost power to the wheels again, I suspect it's some kind of fail safe mode, when I put the car in 1st it takes off with normal power, but in 2nd 3rd and drive it's lagging.

Does anybody know what the cause might be? because I'm stumped..

Cheers.

NCArcher
5th Nov 2018, 04:08 PM
It's basically SAFE Mode. Usually caused by a faulty sensor - air, exhaust, pressure, fuel, temp etc. It's seeing an alarm condition from a sensor and restricting the engine output but leaving you enough power to limp home or to the mechanics.
Have a read here:
https://www.yourmechanic.com/article/p0700-obd-ii-trouble-code-transmission-control-system-malfunction-by-spencer-clayton

NedsHead
5th Nov 2018, 07:18 PM
I was hoping the OBDii scanner would narrow it down a little for me, if the fault was caused by a particular sensor wouldn't it give a code that narrows it down to that sensor/circuit? at this stage it could be anything from a faulty sensor to a dead transmission, I'm not to keen to start throwing parts at it to then find out it needs a new transmission.

Are there any other tests I could perform to try and narrow it down a bit? my OBDii has an I/M function, maybe that will help?

SurfinNev
5th Nov 2018, 08:02 PM
I was hoping the OBDii scanner would narrow it down a little for me, if the fault was caused by a particular sensor wouldn't it give a code that narrows it down to that sensor/circuit?

Not as simple as that. For example on the old Toyota Surf which I have it can show a Timer Control Valve fault which could actually mean the timing belt needs replacing as it has skipped a tooth or two on the crankshaft so nothing wrong with the TCV. As for the Astra look for a forum for these as it may be a common problem.

NedsHead
5th Nov 2018, 09:58 PM
I've done a bit of web browsing over the last couple of weeks and another possibility is that the ECU has sh*t the bed, apparently common with the TS astra.

I've been reading the book that came with the OBD scanner and it has an On Board Monitor Test that might help narrow it down, I'll give that a go tomorrow and post the results.

FWIW the service light and symptoms disappeared this morning and then reappeared this arvo.

Darryn
6th Nov 2018, 12:02 AM
Maybe try this forum
https://www.astraownersnetwork.co.uk/forum.php#
My wife has an AH astra and when I needed a bit of help with that found that for useful

SurfinNev
6th Nov 2018, 09:15 PM
The ECU can be removed, opened up and checked for any burnt tracks or faulty caps if you are careful enough. There are places that can repair them.

Karl Robbers
7th Nov 2018, 09:55 AM
The ECU can be removed, opened up and checked for any burnt tracks or faulty caps if you are careful enough. There are places that can repair them.
The ECU is your most likely culprit, TS Astra's are notorious for failed ECU's. You will need to remove the ECU and the ignition barrel, anti theft transducer and supply them plus the key to a repairer. These people can do it ECU Repairs and Testing - AFI Australia (http://www.afiaustralia.com.au/ecu-repairs-and-testing) and I've just sent one off to them for repair myself.
Before you open it up yourself, have a look on youtube, there are several videos showing repair of the Simtec 70 ECU (what you have), it's not pretty in there - surface mount components encased in goop and all manner of nasties, you could well do more damage than good poking around in there.
I can supply the instructions for removal of the components and beware, you will need to remove the airbag and steering wheel. There is a procedure to disable the airbag.
The ECU repair will probably be around the $500 mark. Another option is to get a second hand security matched set off Ebay. I've seen them as low as $250 and as high as $500, alternatively, you could get a new replacement ECU for $500-$1500, but that will mean getting it coded, which AFI can do provided it is unlocked (ie, not been coded for another vehicle already).

NedsHead
7th Nov 2018, 12:21 PM
Thanks Karl Robbers, how can I be sure the ECU is the culprit?

Karl Robbers
7th Nov 2018, 12:36 PM
Thanks Karl Robbers, how can I be sure the ECU is the culprit?
Well, basically by the process of elimination. Was the error code P1985 or P1895? P1985 as posted originally is an oxygen sensor fault, while 1895 is the actual torque fault that you mentioned?
I cannot categorically state that your ECU is fried, but they are known for it. For some reason Opel thought it a brilliant idea to mount an ECU in a hot place with lots of vibration.
Go through the trouble shooting process and replace the cheap things like sensors first. There are many forums dealing with Astra issues and you could also search the OBDII error code online. That's what I did with mine and it led me back to the ECU.

NedsHead
7th Nov 2018, 05:42 PM
Well, basically by the process of elimination. Was the error code P1985 or P1895? P1985 as posted originally is an oxygen sensor fault, while 1895 is the actual torque fault that you mentioned?

Yeah I gave you the wrong code, it's P1895

NedsHead
8th Nov 2018, 07:43 PM
Here are some pics of what I'm seeing on the scanner today, the I/M list doesn't mean much to me, but maybe it does to somebody else...?

376770376771376772376773376774

This one is from yesterday after clearing the fault codes so may not be relevant.
376769

nadroj
24th Jan 2019, 09:22 AM
You mentioned a fault with the MAF - Mass Air Flow sensor.
I had a Volvo V70 that had that fault, as indicated by a cheap OBD2 reader. It wouldn't start reliably or run right.
Spray cans of MAF cleaner can be bought, so I tried one to no avail - $22 wasted.
Later, I found a brand new, Chinese made, correct MAF sensor on ebay. It cost $20 delivered, and fixed the problem.
Volvo is a Chinese company, after all.