SOLVED: Camry CSI 4cyl 1996 ECU injector problem

[Sploddy]

I had my 1996 Camry fully serviced prior to a 2 week holiday in the South of WA. During which the car ran well.

Returning on the 21st Feb we got 50K out of Albany and the engine lost power on 1 & 3 cylinders near Mt Barker. Towed into the local service centre, it was found that the power transistors/FETs in the ECU providing the power to the injectors had blown. A replacement S/H ECU was located, tested and installed and a week later on the 27th Feb we resumed our journey home... 20K out of Mt Barker going to Perth, the ECU failed again. Same fault. They came out towed us back to town, but could not fix it.

Later in the afternoon we were lent an old Holden to get our Camper Trailer and family back to Perth.

The Mech and the Auto Electricians (next door) do not seem to know why/how/the fault can be fixed. Why an identical fault should occur on a separate ECU.

As a retired electronics Engineer (Radio) I do not know much about auto electronics, but have a strong grounding in electronic theory. If a power Transistor/Fet fails in a power switching cct then there is only one or two things that can cause it. A dead short across the output or a power surge supplying the device.

They say that the resistance of the injector coils read around 14 ohms, which is correct and that no short cct is present. However this is in the engines static and non operating condition.

(This is my first EFI car, previous, 1972 TA22 Celica I had for 25 years!) I am not aquainted with what other devices are in the same line (chain of command) that present a load on the power Transistor/Fets mounted on the housing inside the ECU box. -- As of today 7th March2015, my Camry still sits in Mt Barker with no progress nor information as to when it may be fixed. (I am beginning to feel like a mushroom - kept in the dark and ....)

Has anyone experienced this problem or knows the answer so I can enlighten the mechs at MB?

.

Edited March 7, 2015 by Sploddy

[trentmeyer23]

Has any testing been done on the wiring loom?

The circuit is so simple it's not funny. Power one side of each injector, which is the same 12V source that supplies the ignitor; and a pulsing source to the other side from the ECU. Injectors No. 1 & 3 are paired together and so are No. 2 & 4(called batch-fire injection). The only components are the injectors, ECU and the 12V wiring source.

[Sploddy]

I am having difficulty communicating with the mechanic as the car is some 300 km from my home. However after the first failure, I understand that they did resistance tests on each of the injectors and checked the wiring loom from the ECU to them.. If the wiring is so simple, why would a completely different ECU perform perfectly for 20km and then again blow the output devices.? The replacement "computer" listed on the invoice, which I understand was second hand set me back $462.00.

I am having difficulties obtaining information on what they have actually been doing this past week.

.

[trentmeyer23]

$462? They can be had for a quarter of that price. It would have almost cost you as much to get the car freighted home.

The wiring IS incredibly simple. Testing the wiring loom(for short circuits) and the alternator regulator(for overcharging) would be a good idea.

[(mr2)]

Wow.. that price for an old ECU is a crap load! At that price there must be some kind or warranty if it was the same mechanic that diagnosed the issue.

Do you have the part number for it? You will be able to pick one up on ebay for waaaaay less..

[Sploddy]

Mt Barker is a one horse, two pub town of 2800 and 50 k's from anywere in any direction.. North of Albany WA. Same one mech same one and only car service centre. We had extremely limited internet via mob phone/tablet. Stuck in a caravan park 1.5k outside of town.

As said it took a week to fix the first fault which failed within 20km of second attempt to get home. As of last Friday a week after the 2nd failure, they have apparently done nothing. Maybe next week is all the info I could gain from a call to them. Emails to the Auto Electrical next door, have all been rejected by the mailer daemon and fatal non delivery. I have sent an email to the Service Centre today, which so far has not been "bounced" I have also obtained online a detailed car electrical plan which clearly shows the information given by the Moderator above (thanks)

I have also checked EBay and found 3 possible compat ECUs $75 to $150. I have the car VIN and will try on Monday to obtain the part/serial number of the original ECU.

I will also check the local Perth Toyota "wrecker ring" and see what's available.

I agree that the subsequent fault should be covered under warranty by Australian Consumer regulations regarding supply of faulty goods and/or services and have downloaded a Govt of WA Consumer Practises complaint form if I meet any problems. Three weeks is beyond beilief to fix a simple problem as I now understand it to be.

I am back in Perth, 300km north of Mt Barker, so its not a case of nipping round the corner to check the car out!

Being a disabled aged pensioner doesn't help the situation either financially nor physically.

Ideally I need a good replacement part and qualified mech to go down with me and fix the problem properly ouselves.!

Edited March 8, 2015 by Sploddy

[trentmeyer23]

I would suggest hiring a car trailer and getting someone with a suitable car to help you tow it home.

On another note, the Camry is not a very well suited car for towing, especially the 4 cylinder models.

[OldMech]

I started my (3 years only) motor mech apprenticeship 1946,. RAAF radio / radar 7 yrs,. then TV service very many years, b'cast radio studios operator etc, etc now retired..That's why I was not too unhappy when I bought my 'latest' s/hand Camry a few years ago and found out it was the last of the carby models. . Driven around Aus twice in Sigma wagons. K.I.S.S.!

Certainly i would get the vehicle back to Perth and to an authorised Toyota agency. But even then - who can one rely on nowadays. Perhaps the original diagnosis was wrong and now any service, repair, approach is going around in circles.

Our 'cleverness' brings with it very tricky troubleshooting.

Good luck.

Laurie Edward ... on Facebook.. Rottnest Island etc my favourites. VirtualTourist.com 'australia2'.

[trentmeyer23]

Certainly i would get the vehicle back to Perth and to an authorised Toyota agency.

They will likely not be the best option. They will most definitely be the most expensive option.

[OldMech]

Yes Trent, 'the most expensive option'... .that is sadly for sure.

Repeating faults with solid state is a rotten problem. My 'vacuum tube valve' time was very different.

No second chance or time to measure things with solid state. Bang, thats it!

Edited March 8, 2015 by OldMech

[Sploddy]

I will wait and see if I get any response to my Emails. Although the car is manual, there is no way a tow could take place over 300km It was hairy enough over 20km with the camper trailer fully loaded behind me Even so had to have the engine idling on 2 cylinders to maintain brake pressure. Only method would be a car transporter service, one runs regularly from Albany to Perth with a 6 car semi. or a hire urself car trailer as suggested.

Laurie: I had 7 years in the RN in communications, (1950) then 10 years as an UK cop then came to AU.in 68. Worked as B'cast stn as tech, Oil rigs Radio Operator, then in marine and land radio communications, sonars, auto pilots and. radars. Forced into retirement in 1989 following medical problems - Yeh those bright emitters were indestructable! I still run valve equipment on ham radio (Drake Twins series 4 with a Heathkit afterburner that really heats up the shack)

[Jim.]

My first thought after reading the posts so far, is to check the alternator output voltage like Trent suggests. If it is overcharging, that can blow power transistors.

However, it is still a curious fact that # 1 & 3 have failed for the second time. This would indicate a wiring fault. Rats can eat through wires and I have to keep rodent poison up to my engine bay to keep them under control. If some insulation is eaten away from a wire, it could short out to chassis intermittently. A simple multimeter check will not reveal this, as you will know, and a visual check of the harness/loom would be required to eliminate this possibility. Physically challenging task due to accessibility problems.

I'm now glad I have a spare ECU for my 5SFE 1993 Camry!

edit:

Is your model engine a 5SFE?

Edited March 8, 2015 by Jim.

[Sploddy]

"Is your model engine a 5SFE?" No Jim, understand the FE is the twin cam 16 valve version mine is prior to that. Manual 5S (Engine # 5S41***12 VIN 6T153SK**********) .

I have had the vehicle for just on a year, It was in good condx with little cosmetic wear and had been kept in a garage since new and regularly serviced. and the engine very clean with around 258K on the clock. It performed fautlessly since buying and at the start of the summer I had the cooling system fully flushed, checked and was spot on, never went beyond mid way on guage. The A/C was excellent.

Prior to our holiday, I took the car to a local reputable Service Centre and asked them to go through it thoroughly. They commented that there was a minor oil leak that needed future attention, that the shockies would be required to be replaced and the rear tyres were approaching the wear bars but had a bit more life and in good condx.

They fixed a large number of minor issues, replacing the hood struts, battery and CV joint rubbers. Plus replacing protective sleeving on certain cabling. In addition to the regular replacement of all filters and oil change. The Owner of the Service Centre said they felt the car was in a satisfactory condition to undertake our trip towing the home made camper (Modified 6x4)

As mentioned above I have sent the current repairer a couple of emails, politely suggesting possible harness wear by chafing, and other suggestions made by TOC members. I have also asked him to provide me with the Pt/Ser number of the original ECU, though I do have the VIN etc which should be sufficient.

I have also checked out our local "UHaul" car trailer hire and can obtain a 24 hour hire for around $125. My eldest son, a project Manager with BHP has a 4WD and lives at Mandurah.WA

Hopefully he will be home during the next week. If it comes to the crunch and bringing the car back, he can hire one in Mandurah take the trailer to Mt Barker direct and I can take the loan vehicle down from Perth, returning together.

Photo of car at Arthur River Feb 07 15

[Hiro]

"Is your model engine a 5SFE?" No Jim, understand the FE is the twin cam 16 valve version mine is prior to that. Manual 5S (Engine # 5S41***12 VIN 6T153SK**********)

That _is_ a 5SFE - Toyota never made a single-cam version of the 5S.

[trentmeyer23]

100% 5S-FE.

5S stands for the block designation.

F stands for the Economy head.

E stands for EFI.

[Jim.]

I thought it would be. My earlier one is a 5SFE as I have said. Have another look on the compliance plate.

I know I mentioned rats before. But has there ever been evidence of rats in the engine bay?

Edited March 9, 2015 by Jim.

[trentmeyer23]

Plus replacing protective sleeving on certain cabling.

Certain cabling? Please elaborate.

[OldMech]

Sploddy, next time (?) I'm over your way it would be good to get together and swap occupation history stories... You really have stinker of a problem with your Camry. I am very friendly with a service guy at Cannon Toyota here in Melbourne. But it's amazing how even those 'experts' are not ofay with a lot they should not be.??. Yours is an especially tough problem as it's a 'sort of' intermittent fault. The very worst kind!!.. I have Perth and Freo Friends on Facebook. I love that part of Aussie. A lot of people from the 'Old Country' arrive and settle there.

Laurie Edward - on Facebook..

Edited March 9, 2015 by OldMech

[Sploddy]

I am closing this topic as I received information today that the service centre still has not fixed the problem and is "waiting" for information about the system from the Easten States**...I have stopped all future work and activity on the vehicle.

I have arranged with my eldest son to hire a car trailer and he will take that down behind his Land Rover 4WD and bring the car back to Perth. Tomorrow I will be picking up a compatable ECU from my local wrecker, who has two of them in stock. When we get the car back I will get reputable mechanic who fully understands EFI and especially Toyota, to fit the device.

I also now have the Haynes Manual for the 96 5S FE 4i Camry. Which has all the appropriate wiring and operation information.

I still have all my electronic test equiptment, including a scope and will do a complete 'short' test, voltage and resistance test myself. including checking the alternator regulation and the ecu/injector harness prior to taking it to a workshop.

Thanks all for the assistance, suggestions and support.

Dave

** No one told 'em the three wise men died a long time ago :)

[trentmeyer23]

You're closing this?

[Sploddy]

"So, you are going to leave people hanging and not provide a solution to help them if they encounter this issue in the future?"

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Unfortunately no one on here has the answer. and if "qualified" Auto electricians and mechanics cannot find the solution, what chance have I in resolving the situation? If members wish to continue the discussion that is their choice. ATM I have no further input or substantial contribution and spent many hours searching the internet and asking other people and have found that this fault appears to be unique. I cannot find a single instance of its occurrence anywhere!

It is a fault that presents itself under circumstances which absolutely no one has experienced nor has any reasonable suggestion as to fixing it because no fault cause is presenting itself..... As a Radio Technician I experienced far more complicated problems than this in a prototype "Scanning Sonar" by Feruno and installed the very first one on a prawn trawler in Australia for Kailis Bros It failed to work, it was only after a 72 hour phone hook up with the the design engineers in Japan, was it discovered a wrong part had been installed on a cct board. The error was corrected and the trawler sailed for Darwin an hour later from Fremantle. That was a close shave!

I am advised that the entire ignition and fuel system checks out OK and is within specifications.

Why after two occasions of running for an hour and then after being replaced, for 20 minutes would two different ECUs blow the power transistor/FET to the injectors 1 and 3. As you, Trent, commented in your first response. "The system is so simple its laughable" Well after three weeks of trying to get it fixed I regret to report. I do not find anything laughable about the situation.

The car will be back in Perth in just over a weeks time. If, by any chance either I or my local mechanic has a positive result or answer, then I will gladly post the answer on this forum and share it. Until then have a nice day maybe CYA later...:)

[Jim.]

I am closing this topic.........................................

I also now have the Haynes Manual for the 96 5S FE 4i Camry. Which has all the appropriate wiring and operation information.

I still have all my electronic test equiptment, including a scope and will do a complete 'short' test, voltage and resistance test myself. including checking the alternator regulation and the ecu/injector harness prior to taking it to a workshop.

....................................... :)

I at least, respectfully hope that you do not close this thread until the cause of the problem is found and the problem remedied. It will be found if you perserve, which it seems you will. Several of us respondents have some considerable interest in seeing this resolved as well as you.

What will be of interest to me and others (as well as you) is the results of your tests above.

There is still one question that Trent asked to be answered, the one about "certain wiring". This suggests the possibility or likelyhood of some insulation damage somewhere. If I were you, I would be doing a very thorough visual inspection of any such replacement and asking the mechanic who did it which wiring it is, that is if it is not obvious from a visual inspection.

"Unfortunately no one on here has the answer."

We are limited to the information that you provide for us. Apart from the unanswered question above, I still have not received an answer about any sign of rat infestation in this cars history. My mechanic pals in the town where I live report that they wreak havoc on automotive wiring in these parts. They love insulation; I've no doubt you already know this. If one of the wires to 1 & 3 cylinder (batch firing system) has damaged or eaten through insulation, the output transistor of the ECU may be shorted with movement intermittently. I don't have to explain further to you how that can cause them to fail; you are clearly more qualified than me in the relevant theory here.

You don't have the car with you (yet) and we don't have answers to outstanding questions. So, cut us all a bit of slack please and hopefuly we can continue this process with you when you get the vehicle back at your home.

Let's keep talking..............

Jim.

edit: I am wondering if the output transistors themselves can be replaced in the ECU? I have a spare in the shed, if I get the time today I will open up the case and see if they are accessible. If so, it could result in a cheaper and easier fix of the ECU itself at least.

Edited March 10, 2015 by Jim.

[Sploddy]

I thought it would be. My earlier one is a 5SFE as I have said. Have another look on the compliance plate.

I know I mentioned rats before. But has there ever been evidence of rats in the engine bay?

Noted Jim: as far as I could see the main wiring harnesses were in good condx, in fact a couple of service guys commented on how clean everything looked under the hood. The only issue with wiring were two individual cables (single pair each insulated embodied within an outer sleeving similar to twin insulated mains flex. these came either side of the exhaust manifold and ran downwards.

I understand that these came from 2 sensors and went to a harness at the lower engine level. Due to their close proximity to the exhaust system the outer sleeving had hardened and cracked. (To be expected after 19 years). The inner wire sleeving was in good condition and operation checked. The cracked outer was carefully removed and replaced with "Spiral wrap" a free fitting protective sleeving like a coil spring and secured away from the heat source with cable ties.

(Spiral Wrap is also used in larger diameters for restraining computer and audio cabling - very useful where original cabling cannot or is not desired to be disconnected)

I will point out that the guys who carried out the preholiday check went through the car like a dose of salts, right down to unblocking a partially glogged windscreen washer. I gave them carte blanche to fix any issue they found. When we returned from holiday it was our intention to carry out two further issues by replacing the shockies and new set of tyres. they also checked out my trailer as well.

Probably my term close the thread was not the appropriate term to use. I just wanted to back out and prepare for the next phase when I got the car back to Perth. Each and every one of us are different people with different circumstances, some can afford to buy a new car every year, others rely on "OPJ" cars (Other people's Junk). 26 years ago I was told I had 30 days left to live ---. I have just turned 80. In 1988, I was Service Manager and senior technician for an electronics company in Perth. The medical procedures I went through then and during the following 15 years resulted in me ending up on disability pension aged 54. Including a run-in with cancer, but I beat the lot. However the cost financially and personally was extreme. I have never sought sympathy nor finanicial assistance. I came through on my own with a strong will and determination. My web page which contains "my Story" has had over 11500 hits. Not bad for a private blog and I have had messages from many people all around the world.

Anyway I digress and maybe this should be on a different page :) But anyone who wants to read it Google "The Smithdale Pages" and go to the "TPG" site I am in the process of transferring and re-writing some of the pages to my own server which is also listed at (dsmithdale.net) This carries hobbies I took up during the last 25 years as occupational therapy, including building very large scale warships.

Final note. Jim, yes the output transistors can easily be replaced. as of now I do not know their part number ie 2SD1234 etc but I have a source in Hong Kong [uTSource} which can guarantee supply of a direct replacement or even a higher powered rating depending on whether they are Darlington Power Transistors or High power switching FETs. As mentioned elsewhere I have designed & built PWM speed controllers for my model ships using Power FETs rated at 80 amps (CCS) (Continuous Commercial Service)

The supplier can meet orders from 1 to several 1000 and are extremely cheap. Not only Transistors and Fets but virtually every conceivable IC or device, both obsolete and new. they are also extremely quick in posting and delivering.

http://tinyurl.com/d3zxc26

The Power devices are mounted on the side of the case. Due to sensitive CMOS devices, anti-static precautions should be taken when handling the circuit board. Under no circumstances touch or probe any of the devices other than given test points with grounded test equipment. Many people laugh at this, but in the trade, there is a saying, "If in doubt, work with one hand behind your back" Being carbon based we can generate quite a large amount of electricity in our bodies! An earthed wrist strap is not a joke :)

To prevent damage to the board use the lowest heat that will melt the solder using "Solder Wick" available from Altronics/Jaycar etc. DSE no longer sell electronic service aids. Once the solder is removed, unbolt the device from the heat sink. Use hi quality heat sink paste/insulator pads when replacing and ensure spotlessly clean surfaces, but do not use abrasives.

Edited March 10, 2015 by Sploddy

[Sploddy]

Trap for Young Players!

I obtained an ECU this morning plus a set of connectors. My analysis of the CCT inside the box show the following path:

IC101 which is a Denso Error Amplifier ( Pt# is SE145) output goes to a Transistor T101 a 2SB1453 this in turn drives the two output Transistors T803 (1&3) and T804 (2&4) both 2SD2162.

These are the output power transistors and connected to terminals #10 and #20 these are on the longer socket to the left of the box near the transistors. However also in parallel with these pinouts is a resistor R822 and R823. and associated capacitors C802 and C804. The two wires from #10 and #20 on the plug are yellow and white.

If either of the transistors blow, it should be necessary to check these resistors/capacitors as they may be the cause of the failure.

It is needless to say that if the connector is not plugged in, then the test result is not going to show abnormal at the injectors. If the cable is connected then there is a strong possibility that the reading may or may not be affected if the appropriate suspected transistor is blown. When transistors blow the can exhibit either an open circuit or a short, depending on what happened. It would be necessary to check the associated circuitry on both Power Transistors, comparing their paramaters.

It would also be necessary to check the parallel components on #10 and #20 output pins in the ECU as these may be the cause of failure. Resistors when aged can change their value or break down. Smilarly capacitors which are used to eliminate spikes and ripples can eventually break down and short out or not do the work of spike suppression.

The mechanic at the wreckers strongly recommended not using the original cabling (yellow and white wire) but to cut them close to the plug and patch in at the cut wire and run a separate pair. He said the ECU came off a fully operational engine and therefore taking this precaution it should work. eliminating any intermittent shorts in the harness.

The unused wire ends should be heat shrinked to prevent shorting anything at either end and tied back with a cable tie.

By searching UTSource for 2SD2162 and 2SB1453 a manufacturers data sheet is available and they are priced from a $1 each! The 2SD2162 is an NPN 50V 7A device the 2SB1453 is a PNP darlington switch Transistor.

When I get the car back I will compare the new ECU with the old original one (if I can get it back)

(Edited -- UTSource has all of these semiconductor parts in stock. - The resistors on pins #10/#20 are marked 270 (Ohms?) and the capacitor 155K which is 1.5 uF 400v CBB cap similar to greencaps.)

Edited March 11, 2015 by Sploddy

[OldMech]

Find an experienced specialist expert. Surely somewhere around Perth there is one.

I gave up the game partly because of solid state servicing problems. But many of my tech friends did OK.

Good luck whatever you do.