Any good shops that do computer re-programming?

[Graham_A_M]

Hey guys, the check engine light was on in my '99 S10 (with the 2.2L 4cyl). Its pulling a myriad of different codes, mainly on sensors that were just replaced and that I know to be good. The mechanic who did the diagnostic basically said I'd most likely need a computer reprogramming.

I know the dealerships will rape me viciously if I get it done there. So is there any places that can do this sort of thing elsewhere?

Thanks a ton for reading this and offering any help you can.

[spike98]

Hmmm never heard of "reprogramming" a ECU with the exception of "chipping" for performance gain. This usually just changes operating parameters of the engine and tranny.

If my understanding is correct when a ECU throws a code, the code is stored on a bank of memory to be read. This memory can be clear and the codes stored purged.

Now you "should" be able to clear the codes via a standard code reader with the exception of the newer CAN-BUS interface ECU's. But that can be remedied with a different scan tool that many shops should have.

Sometimes this can also be achieved by disconnecting the batter overnight as well.

[Sentry]

There might be an updated cal file for the ECU, in which case it would have to go to a dealer.

[HO2S]

Originally posted by Sentry
There might be an updated cal file for the ECU, in which case it would have to go to a dealer.

You don't have to go to the dealer, You can buy a one day subscription to any manufactures programming site. All that you do is download the vehicle's vin and calibration ID onto your pass through flasher then connect to the website and it will tell you if any updates are available.
I can do it, but I'm booked solid for like 2-3 weeks. And I would re-diagnose before I did any sort of programming or replacing of parts because some one else said it needed it.

[anomaly2]

What are the codes the engine is setting?
What is the VIN of the vehicle?
Thanks...

[Graham_A_M]

VIN? I dont know off hand. I can get it if you need it. But its a '99 S10, 2.2L 4cyl, 5 speed manual. (etc etc)
The codes its pulling is
-a low sensor output of the TPS. I JUST replaced it about 6k kms ago
- RF speed sensor erratic history
- Cam shaft position sensor A circuit. He said problematic starting may be caused by this, but its always started perfectly fine, so that's not likely the problem.
- Catalytic Converter, although this was JUST replaced 200km's ago.
- plus another couple.

Originally posted by HO2S

You don't have to go to the dealer, You can buy a one day subscription to any manufactures programming site. All that you do is download the vehicle's vin and calibration ID onto your pass through flasher then connect to the website and it will tell you if any updates are available.
I can do it, but I'm booked solid for like 2-3 weeks. And I would re-diagnose before I did any sort of programming or replacing of parts because some one else said it needed it.

Sure, if it comes back on I'll PM you. How much would you charge for this? Apparently there are a couple updates and issues that need to be addressed while doing this.

[AE92_TreunoSC]

Usually ECU reprogramming just changes parameters for a very few specific issues.

I've been diagnosing for years, some years were chevys and not once did I ever find the need to reprogram an ECU because of such issues.

Usually you reprogram only as a last resort or because of a bulletin.

Now time to think and type.

The R/F speed sensor is very very common on chevys, usually play in the wheel bearing causes the intermittent failure.

TPS could be a bad unit out of box, or misadjusted or misdiagnosed. Or circuit issues.

Cat can be multiple things. Aftermarket cats have a horrid rate of failure out of box. Also if the O2's are reading incorrectly it can inadvertently tell the ECU the cat is not converting. P0420 is the cat 90% of the time, but there are 10% of the time where its an outside cause. Possible Cricuit issue.

The cam shaft circuit has me thinking a possible shared circuit issue. I would use a schematic and see what sensors share what circuit. Often a bad circuit sharing a 5v source with the others can cause a huge array of problems. The last time I saw this was on a Nissan. I got 5 codes. Cam, AFM, TPS, Evap purge and one other. I traced the circuit and found a broken wire leading to the A/C pressure switch, it shared the 5 volt circuit and was creating a short to power to another circuit.

So perhaps inspect the sensor reference voltage, the sensor ground circuit. Much easier then reprogramming and more likely.

[Discombobulator]

If the guy didnt clear the codes, the computer will only clear them itself after a set amount of successful start with no abnormal readings from the sensors that were changed ( somewhere around 50 starts usually ) Simply try unplugging your battery, and hold the brake pedal for 15 seconds then reconnect the battery. You hold the brake pedal to drain out any power stored in capacitors inside the ECU or elsewhere in your vehicles electrical system. If this doesnt work then you either still have a sensor problem ( just because the sensors are new doesnt mean the problem was adressed - what if it was actually a faulty ground wire that your mechanic misdiagnosed? ) Or maybe but highly unlikeley an ECU problem. Let me know what happens i have a code reader if you need and am a certified technician

[firebane]

I'd be getting a second opinion. As stated by someone did the TPS itself get checked for proper voltage at open and closed? Did it get readjusted?

To give you an idea of how codes are so difficult to diagnose I have a 1998 GMC with the 5.7 and the CEL light was on. I scanned the system and it showed secondary O2 sensor was failing which is the one usually in front or behind the 2nd cat.

I was about to replace this O2 sensor as per CEL but did some maintenance to my truck which included new cap and rotor and after I cleared the codes the CEL went away.

From this I ultimately assumed that because the distributor was causing some crazy timing issues that it was making the truck run probably a tad on the rich side.

Something like this get a 2nd opinion.

[HO2S]

For some silly reason I cant log into alldata so I can't check to see what the updates are for, but from what you descried updating will not fix the problems you are having.

GM tps are shitty, even the aftermarket ones. They fail all the time. Ive had ac delco ones be bad out of the box. This is a GM not a import so there is no adjustment available for the sensor.

Aftermarket cat's can set efficiency codes, There is a reason why the dealer part is $1000 and a aftermarket one is $200. If you don't want to spend the coin to get a oes part try a different brand than what you have right now.

The other tech was saying that a bad cam position sensor can cause hard starts, that is true but its more like a long crank. If you don't have cam sensor input the pcm needs a longer crank to find cylinder one. Seeing that you don't have a long crank its probably a bad sensor that is shorting for a split second. Your going to have to get the circuit scoped to see that is going on.

The erratic speed sensor signal could be from a loose bearing(like what AE92 said) or corrosion under the wheel speed sensor on the hub unit. The other harder one to find is the wheel speed sensor wires like to break usually a few inches away from the sensor on the control arm. The wire will start to break and only one strand will be left in the wire. It will pass the continuity test but set a erratic code.


At my shop, our hourly rate is $130. It would take me a hour or two to diagnose all of said problems. For programming and updating I think we start at around $200 or so.

[Graham_A_M]

Alright, thanks so much for all the updates and help.

A bit more background, yes the Cat was aftermarket. GM wanted an ass-ton of money for one, so I went aftermarket. Oddly enough though the computer is still pulling a code on the O2 sensor, which is well within proper parameters. I forget how he explained it, but at idle & high RPM, it was reading properly.

AE92 & HQ2S is right, the front bearings have a bit of play to them. Not NEEDing to be replaced, but when I went in for an alignment they pointed that out. Would that be the cause of the RF speed sensor issue most likely?

For the Cam postion sensor, thats the second time it was scanned that this code came up. (both scans were done at same shop a month away from eachother). Its odd though, none of the symptoms that would point to that sensor being faulty as present though. It starts fine, after half a second of cranking the key each time. Its never been an issue. Just wondering how hard that sensor is to access. Its the same 2.2L in the Cavalier & Sunfire.

For the TPS, any other signs I should look for? I bought an OEM AC Delco one, but it could have been still faulty. I installed it myself, since it was very straight forward, sure would be a piss off if that was faulty right from the get go.

[HO2S]

If the bearings have any play, they should be replaced.

There are many other things that can cause o2 codes besides bad sensors or a bad cat. You can go into mode 6 and see exactly why the code was set. Codes don't just set for no reason.

Cam/crank sensors are monitored continuously, the sensor only has to drop out for a millisecond to set a code. The only way that you will see it is on a scope.

[anomaly2]

Is this a S10-pick up truck 2 wheel drive or a S10 Utility or T truck 4 wheel drive vehicle? If its a 4wd drive or utility
then the speed sensor is part of the wheel bearing but if its only a S10- Pick up truck rear wheel drive the front wheel bearing needs to adjusted specification, and the speed sensor is part of the backing plate. Thats why the VIN is needed, which code for 02 sensor , tps, catalytic converter
DTC P0131 O2S Circuit Low Voltage Sensor 1
DTC P0132 O2S Circuit High Voltage Sensor 1
DTC P0133 O2S Slow Response Sensor 1
DTC P0134 O2S Circuit Insufficient Activity Sensor 1
DTC P0137 HO2S Circuit Low Voltage Sensor 2
DTC P0138 HO2S Circuit High Voltage Sensor 2
DTC P0140 HO2S Circuit Insufficient Activity Sensor 2
DTC P0141 HO2S Heater Performance Sensor 2
DTC P0341 Camshaft Position (CMP) Sensor Performance
DTC P0342 Camshaft Position (CMP) Sensor Circuit Low Voltage
DTC P0420 Catalyst System Low Efficiency
DTC P0122 Throttle Position (TP) Sensor Circuit Low Voltage
DTC P0123 Throttle Position (TP) Sensor Circuit High Voltage
Check terminal grip and wiring for chaffing to ground or broken wires inside insulation near each connector, hold connector and tug on the wires. Also does this vehicle have Air conditioning check for , A faulty A/C sensor could set a DTC P0122. Disconnect the A/C electrical connector.

CMP sensor is located on Right hand side of engine close to oil filter,
sensor goes into the side of the block may have to remove right wheel to access. 3 pin connector terminal A Red crt 631 cmp sensor B+ battery voltage, terminal B Pink Black crt 632 cmp ground signal , terminal C brown white crt 633 cmp signal circuit.

[HO2S]

Originally posted by anomaly2
Is this a S10-pick up truck 2 wheel drive or a S10 Utility or T truck 4 wheel drive vehicle? If its a 4wd drive or utility
then the speed sensor is part of the wheel bearing but if its only a S10- Pick up truck rear wheel drive the front wheel bearing needs to adjusted specification, and the speed sensor is part of the backing plate. Thats why the VIN is needed,

Oh, I forgot about 2wd. If its 2wd it has to have a little bit of play. But if its 4wd then no play is allowed.