4L80E High RPMs?

[Gordonr1973]

Hi all;

just about to do some trouble shooting on my transmission.

Yesterday was the first time I took the truck (LQ9 motor with new Comp Cam) out for a drive on the freeway.

I bought the tranny as a pullout from a cargo van with about 20,000 miles on it.

I didn't build the tranny up at all, other than to change its filter and fluid.

On the freeway yesterday it seemed not to want to shift out of 3rd to fourth??

I was driving about 45 to 50 mph and the tach was showing inbetween 3k to 4k RPM.

Any suggestions on what to check for? I thought it might be a case of low Auto trans fluid but I checked it & that seems to be fine.

Could this be something corrected by a new PCM tune (which I haven't had the final tune done yet) of the shift points?

Thanks!

[BR3W CITY]

do you have tires or wheels that are drastically different than stock (stock for the DONOR vehicle)? Tire size will throw off shift points.

You may also want to have the pcm checked for the lockup settings....it honestly sounds like you aren't getting top gear, or lockup either. At 75 I'm barely at 3k, and I can go less if it locks up (I have a lockup issue as well)

err.....what rear gear do you have?

[Gordonr1973]

3:73 rear gears

The PCM was programmed for my tires 295R22's but I'm going down to a 285R20's this weekend.

I'd imagine the tires are lots taller than the donor as it was some type of cube van.

It totally felt like it wasn't shifting to forth on the highway.

[clinebarger]

Originally Posted by Gordonr1973

Hi all;

just about to do some trouble shooting on my transmission.

Yesterday was the first time I took the truck (LQ9 motor with new Comp Cam) out for a drive on the freeway.

I bought the tranny as a pullout from a cargo van with about 20,000 miles on it.

I didn't build the tranny up at all, other than to change its filter and fluid.

On the freeway yesterday it seemed not to want to shift out of 3rd to fourth??

I was driving about 45 to 50 mph and the tach was showing inbetween 3k to 4k RPM.

Any suggestions on what to check for? I thought it might be a case of low Auto trans fluid but I checked it & that seems to be fine.

Could this be something corrected by a new PCM tune (which I haven't had the final tune done yet) of the shift points?

Thanks!

Default/Limp mode is 2nd gear ONLY on a 4L80E...Are you sure its taking off in 1st gear?
Is the trans plugged in? ISS? VSS? Codes?

Originally Posted by BR3W CITY

do you have tires or wheels that are drastically different than stock (stock for the DONOR vehicle)? Tire size will throw off shift points.

You may also want to have the pcm checked for the lockup settings....it honestly sounds like you aren't getting top gear, or lockup either. At 75 I'm barely at 3k, and I can go less if it locks up (I have a lockup issue as well)

err.....what rear gear do you have?

Sounds like its not shifting into 4th either. Codes?

[Gordonr1973]

Actually, it does seem to chug when I shift it into drive or when I start off from a red light. So it definitely could be stuck in second gear.

Is there a way to fix this?

I willl check it for codes again tomorrow as I'm away tonight. I'll doublecheck wiring connections too.

[BR3W CITY]

Originally Posted by clinebarger

Sounds like its not shifting into 4th either. Codes?

You talking to me cline? I'll check again but I don't remember seeing a code.
We went from a 235/60 (iirc) up to a 325 series mickey ET street. It does lockup, but not always, and it super finnicky. It hasn't been retuned since the tires went on, so I figured it would be throwing off my mph and also my shiftpoints.

I had also discussed the possibility that because my dbw throttle is pretty dang sensitive, and it requires very little throttle to move on the hwy, it might be tossing me out of lockup because it will see a micro rpm spike from hitting a bump and my foot moving slightly. Not sure HOW likely that is, but its touchy and it wouldn't surprise me.

[clinebarger]

Originally Posted by Gordonr1973

Actually, it does seem to chug when I shift it into drive or when I start off from a red light. So it definitely could be stuck in second gear.

Is there a way to fix this?

I willl check it for codes again tomorrow as I'm away tonight. I'll doublecheck wiring connections too.

If all the plug-in's are good, Check for ignition power to the main trans plug *Pin E*.

[clinebarger]

Originally Posted by BR3W CITY

You talking to me cline? I'll check again but I don't remember seeing a code.
We went from a 235/60 (iirc) up to a 325 series mickey ET street. It does lockup, but not always, and it super finnicky. It hasn't been retuned since the tires went on, so I figured it would be throwing off my mph and also my shiftpoints.

I had also discussed the possibility that because my dbw throttle is pretty dang sensitive, and it requires very little throttle to move on the hwy, it might be tossing me out of lockup because it will see a micro rpm spike from hitting a bump and my foot moving slightly. Not sure HOW likely that is, but its touchy and it wouldn't surprise me.

Your RPM's at 75 seem high, How tall is that tire? With a 26" tall tire, 3:73 gears at 3000 in 4th (.75) you would be going over 80mph. 26" tall tires are really short these days.....Makes me think its not shifting into overdrive.

[Gordonr1973]

Hi, there were no codes before I started it up (does it clear itself when the ignition is turned off?)

But now here are the codes it just threw after I started it and put it in gear:

P0200 Injector
P0463 Fuel Level Sensor A (to access the code reader I have to turn off the ignition to just the accessory position without the engine running)
P0522 Oil Pressure Low Reading
P0608 PCM Speed Output A (I haven't calibrated my autometer speedometer yet, but I didn't think that would matter yet)
P0706 Transmission Range Sendor Circuit
P0753 Shift Solenoid A Electrical
P0758 Shift Solenoid B
P1638 Alternator F Circiut
P1810 Transmission Fluid Pressure Position Circuit
P1860 TCC PWM Solenoid Circuit

Now, I did replace my tranny speed sensors when I installed it, are they the same or is there a difference between them that each one is designated front or rear?

Going to check all my connections again right now. And I will check for power on pin E

[BR3W CITY]

Sorry Gordon, don't mean to hijack your thread.

Cline;
Was out today, 70mph (reading off my scangauge, so its what the pcm is seeing) was 2534. The tire is a 325/50/15 so thats almost 28" tall. Maybe your right, I've really only had the thing out a few times total (less than 15 drives, not counting my roadtrip), and since I keep building and changing it, I never established what "100% working" should feel like.

I need to check the selector cable as well, I have a new shifter on the way, and I wonder if the vague (and ghetto rigged) 700r4 B+M shifter isn't actually lined up anymore and not going into top.

Thanks for saying something, I had it in theback of my mind that it should be running lower, but since it hadn't been touched since the tires, never actually made anything of it.

Is there anything else mechanically I should look at? Tuner will be looking at it soon to check for programming issues.

[clinebarger]

Originally Posted by Gordonr1973

Hi, there were no codes before I started it up (does it clear itself when the ignition is turned off?)

But now here are the codes it just threw after I started it and put it in gear:

P0200 Injector
P0463 Fuel Level Sensor A (to access the code reader I have to turn off the ignition to just the accessory position without the engine running)
P0522 Oil Pressure Low Reading
P0608 PCM Speed Output A (I haven't calibrated my autometer speedometer yet, but I didn't think that would matter yet)
P0706 Transmission Range Sendor Circuit
P0753 Shift Solenoid A Electrical
P0758 Shift Solenoid B
P1638 Alternator F Circiut
P1810 Transmission Fluid Pressure Position Circuit
P1860 TCC PWM Solenoid Circuit

Now, I did replace my tranny speed sensors when I installed it, are they the same or is there a difference between them that each one is designated front or rear?

Going to check all my connections again right now. And I will check for power on pin E

P0200....The powertrain control module (PCM) detects an incorrect voltage on a fuel injector control circuit.
Unusual code, Check for proper ignition voltage on the injectors.

P0463,P0522...Swap related codes....Who tuned/flashed your PCM?

P0608...
The powertrain control module (PCM) creates the vehicle speed signal by pulsing the signal circuit to ground. The PCM pulses the circuit at the same rate as the vehicle speed signal input. The PCM monitors the voltage on the vehicle speed signal circuit. If the PCM determines the voltage is out of the normal operating range, a DTC sets.
The PCM detects that the commanded state of the driver and the actual state of the control circuit do not match.
Maybe the VSS output is shorted.

P0706....Related to P1810...No TFP Input...PCM thinks your driving down the road in park/neutral.

P0753....The 1-2 shift solenoid (SS) valve controls the fluid flow action on the 1-2 and the 3-4 shift valves. The 1-2 SS valve is a normally-open exhaust valve that is used with the 2-3 SS valve to allow for four different shifting combinations. The 1-2 SS valve attaches to the control valve body within the transmission. The ignition voltage goes directly to the 1-2 SS valve. The powertrain control module (PCM) controls the 1-2 SS valve by providing the ground path through the 1-2 shift solenoid valve control circuit.
When the PCM detects a continuous open or short in the 1-2 SS valve circuit or the 1-2 SS valve, then DTC P0753 sets. No or low Ignition power will set this code

P0758....Same as P0753, Except its for the 2-3 shift solenoid.

P1638....Is the alternator feild wire going to the PCM?

P1810....The automatic transmission fluid pressure (TFP) manual valve position switch consists of five normally open pressure switches. The powertrain control module (PCM) supplies battery voltage to each range signal. By grounding one or more of these circuits through various combinations of the pressure switches, the PCM detects what manual valve position has been selected, and compares the actual voltage combination of the switches to a TFP manual valve position switch combination table stored in memory.
The TFP manual valve position switch assembly cannot distinguish between PARK and NEUTRAL because the monitored valve body pressures are identical in both cases. With the ignition ON and the engine OFF, D2 is indicated. When the transmission 20-way connector is disconnected, the ground potential for the three range signals to the PCM is removed, and with the ignition ON, D2 is indicated.
If the PCM detects an invalid state of the TFP manual valve position switch circuit by deciphering the TFP manual valve position switch inputs, then DTC P1810 sets.

1860....TCC solenoid code, No/Low power.

You have a electrical problem!

[Gordonr1973]

Jon at PSI Conversions did the intial tune as I bought the PCM from him along with the harness and gas pedal & TAC module.

I wouldn't be surprised if it was a wiring problem as the harness with its loose connectors was a $500 POS in my opinion.

I just finished supper and am going to check pin E now, will print this off and start checking your list, thanks for taking the time to write all of that down!

[Gordonr1973]

I'm getting 4.99 volts at Pin E with the ignition in the 'on' position.

Other connections are tight on the tranny.

[clinebarger]

Originally Posted by Gordonr1973

I'm getting 4.99 volts at Pin E with the ignition in the 'on' position.

Other connections are tight on the tranny.

You need 12.6 VDC at the trans plug....What's the battery voltage?, Maybe it has a 5-volt reference wire feeding power to the trans?

[Gordonr1973]

The battery reads 12.5

Do you mean a type of relay as a 'reference wire'?

I'm not sure, I'm going to find me Speed & Performance catalogue & build book and see what it says if anything regarding the harness.

Any suggestions or should I keep trying to check the other items in your previous response, thank you for all that info!

[gringoloco]

5v is what the PCM uses as a reference for sensors. It sends out 5v to the sensor, then compares what it gets back to know engine temp, etc. It should not be used to power the trans. Possibly the wrong PCM output pin was used to power pin E on your trans connector...
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[Gordonr1973]

Okay. That Pin E wire is very thin, like an 18 gauge or so. Could it handle 12V without melting?

I'm not really sure what to do about this low voltage when it should be 12V as I did not make the LS harness...should I pull it out to run and track wires or try something else?

I was searching threads last night and found some with similar problems.

Would it help to start with buying a new Throttle Position Sensor and cleaning my throttle body to see if the tranny will note better the throttle position in case my current sensor is shot?

[BR3W CITY]

Originally Posted by Gordonr1973

I wouldn't be surprised if it was a wiring problem as the harness with its loose connectors was a $500 POS in my opinion.

Have you let them know you were unhappy with the harness? I've never worked with them, but if I got a **** product from someone...I'd let them knowl

[gringoloco]

The voltage should not be a factor on the wire-- it's the current that you need to worry about-- not sure how many amps the trans draws. Most wires in the factory harness are the same size, except the main power/ground.

I think you may end up having to re-pin that connector. Sux, since it should be correct from the manufacturer. Either send it back to them to fix, or if you don't trust them to do it right, check out LT1swap.com and fix it yourself...

[Gordonr1973]

Originally Posted by BR3W CITY

Have you let them know you were unhappy with the harness? I've never worked with them, but if I got a **** product from someone...I'd let them knowl

I have emailed Jon many times regarding each of the mistakes in the harness and each time I ask for a new harness but he either ignores my emails or delays & delays ... read my build thread for the details if you want. I'm frankly tired of dealing with his sh!tty customer service and I won't buy anything from him again.

Originally Posted by gringoloco

The voltage should not be a factor on the wire-- it's the current that you need to worry about-- not sure how many amps the trans draws. Most wires in the factory harness are the same size, except the main power/ground.

I think you may end up having to re-pin that connector. Sux, since it should be correct from the manufacturer. Either send it back to them to fix, or if you don't trust them to do it right, check out LT1swap.com and fix it yourself...

I've actually got fed up with the harness problems and called Mark from Speed & Performance and told him my situation. He is going to sell me a new harness and FedEx it to me on Thursday once it is finished so there is still a chance I will make the Street Wheelers festival up here on July 14th. In the end, it is always a case of time or money....for me I don't have much of either!

In the meantime I will still try to troubleshoot as best I can so I can limp it to the shop tomorrow to get the wheel alingment at least. When I remove the current harness I will trace the wiring exactly to see what's wrong and either fix it, or I will try to sell it with a list of defects to someone who might want to fix it and get a deal on the price.

[clinebarger]

Originally Posted by Gordonr1973

I have emailed Jon many times regarding each of the mistakes in the harness and each time I ask for a new harness but he either ignores my emails or delays & delays ... read my build thread for the details if you want. I'm frankly tired of dealing with his sh!tty customer service and I won't buy anything from him again.



I've actually got fed up with the harness problems and called Mark from Speed & Performance and told him my situation. He is going to sell me a new harness and FedEx it to me on Thursday once it is finished so there is still a chance I will make the Street Wheelers festival up here on July 14th. In the end, it is always a case of time or money....for me I don't have much of either!

In the meantime I will still try to troubleshoot as best I can so I can limp it to the shop tomorrow to get the wheel alingment at least. When I remove the current harness I will trace the wiring exactly to see what's wrong and either fix it, or I will try to sell it with a list of defects to someone who might want to fix it and get a deal on the price.

He will sell you a harness??? Didnt he already do that?

The low power could be on your end. Did you check the voltage at the MAIN Ignition Power source? injectors? MAF sensor?

[Gordonr1973]

The original harness is from Jon at PSI Conversions. That's the harness I had all the trouble with.

Speed & Performance is where I bought my headers and I got way better customer service from them over my build --- even with asking Mark about stuff I didn't buy from his shop. That's why I'm willing to pay for a new harness from him.

I just got in the house here so I'm going to be doing some voltage checking tonight after supper and will post results shortly.

[Gordonr1973]

Okay; here are the current readings:

All injectors read 12.45V
Main Ignition Power 12.45V
Pin E in the trans connector 12.45V (Im not sure why it is different today, maybe I tested the wrong pin the other night)

However, I cannot get a voltage reading on the MAF sensor. I inspected the wires from the MAF connector back to the main LS harness and they look okay and unbroken.

Is there a Pin I can check? Any other suggestions?

[clinebarger]

Originally Posted by Gordonr1973

Okay; here are the current readings:

All injectors read 12.45V
Main Ignition Power 12.45V
Pin E in the trans connector 12.45V (Im not sure why it is different today, maybe I tested the wrong pin the other night)

However, I cannot get a voltage reading on the MAF sensor. I inspected the wires from the MAF connector back to the main LS harness and they look okay and unbroken.

Is there a Pin I can check? Any other suggestions?

Heres a MAF pinout.

OK, 2 different outfits.

So you have trans power? Do you have power while cranking? The Injector & Trans codes point to a ignition power problem.... Wiggle test the harness to see if you lose power.

Look at the trans harness connector (the plug on the trans-side.) for bent pins.

It could be some other things, Like a mis-pinned harness, Internal trans harness issues.

[Gordonr1973]

Wiggle test: It feels like the plastic connector portion on the tranny (what the large round harness plugs into) is loose --- so loose that I can push it into the tranny somewhat but I didn't push it so far to check if it will fall in the tranny yet.

Maybe it is causing the problem? I am search the internet to see if I can find a diagram of what is supposed to be the backing to that piece inside the tranny.

Is that piece replacable without pulling the tranny down and going through all the internals?