I've had this topic on here before but can't find it.

While cruising under 65mph, rpm will bounce a couple hundred rpm. Engine will also bog down. If i have my foot on the throttle and tap the brake the rpm will go back normal, but drop right down again. This happens after the car is up to operating temperature.

Could this be the TC locking and unlocking? What about the tcc solenoid?

 

Scan it for codes... there are multiple codes for the 4L60E, and they don't turn on the SES light.

 

I'll scan it but it had never thrown a code and this had been happening forever.

 

It's up to you.

 

Sorry,, i didn't mean anything. Lol

Its just getting annoying.

 

The PCM provides a lot of information about the transmission, including the TCC control and reasons that it is turned off. Note everything pertaining to TCC or shorts or opens in other solenoids are circled in red.

 

Garydoug, is there any way to test my USB cable to see if its bad. Your program and the drivers for the usb installed but i cannot connect in the scan software.

 

Depends on the cable. If there are lights on it, you can do this: Plug it into the car's connector and switch on the ignition. The red LED should be flashing continuously. If it isn't the cable may be defective or miswired.

 

Yeah, it doesn't have a light. I'll try installing everything again. Hopefully i can Get it to work.

 

Many interface cables get powered from pin 16 of the connector, which is provided via the cigarette lighter fuse.

 

OBD1 cars don't use the power from the DLC socket. Even OBD1 handheld scanners have to get power from a cigar lighter plug or ac adapter. These OBD1-USB adapters get their power from the pc. I have never seen an OBD1 adapter without some lights. They may not be visible until lit through the translucent case. The ones I specified in my posts are like that. Normally they flash green and red briefly when plugged into the pc. Then they flash red if plugged into the car with the ignition on.

 

I will check install and post back