The light on my shifter for my auto 4r100 blinks sometimes and runs funny,like the rpm's are high but it hardly accelerates ,but if I turn the truck off and restart the truck the light stops blinking and runs perfectly, I have no idea what's going on. If it means any thing I just had the torque converter replaced.

 

That blinking light signifies that you have a trouble code in the transmission. If you overheated the transmission the fluid breaks down and then the clutchs slip on one another, as well as the disks in the torque converter. This is the EXACT reason that every one of my trucks has a trans temp gauge. I roached the 4R70W in my 97 F150 from overheating it before I had gauges. Since then I've had them, and its very revealing what they can tell you.


If you have high rpms but little acceleration that means that your trans is slipping. What speeds does it do this at? If its at low speeds instead of higher speeds then my thought is that a sensor has failed and is not allowing the torque converter to lock properly. If the torque converter isn't locking enough then you're not going anywhere. If its also slipping like that alot then your fluid is probably toast by now, and hopefully hasn't taken your clutchs out with it. Better get to a good trans shop. Though it would be in your best interest to get the codes read first as it may be a simple fix.

 

i have a tranny temp gauge and it's usually at 150 when driving around and hardly ever gets much hotter than that. today i was getting on I75 and it started blinking and was running weird than as i speed up it went away and yes it is usually at slow speeds. can an motor tuner read my tranny codes as well?

 

Yes it would. The motor is the hard thing to read as it uses enhanced OBDII and the rest of the chasis is plain OBDII. Even Autozone can read those codes with their crappy scanners. Now when you were getting on I75 and it was acting weird, what was it doing and how fast were you going? It sounds like its not locking up right.

 

im accelerating from 0 to 45-50 than the light stoped blinking and it ran fine. It felt like it was slipping through the gears, high rpm's and slower than normal speed for the high rpm's, it wasint responsive ether

 

I used my scanner to read the codes and I got the codes p0720 output shaft speed sensor circuit and p0603 power-train control module keep alive memory error. Can you explain what they mean little more for me, i just want to know what im getting in to?

 

The KAM error is normal and you'll get it as long as you have a programmer on the truck.

The output shaft sensor would make me think that the sensor has failed or is blocked. If there is excessive metal in the trans it could have collected on the sensor (magnet) and is preventing it from seeing the tone ring. My thought is that the PCM is not seeing the output shaft speed it wants to and is not locking the torque converter in.

 

it is acting like it is not locking the TC