Engine light diagnosed as ECM. What is your thought.

The problem you're experiencing with your 1999 Lexus RX 300, where the vehicle loses power until reaching 40 or 50 mph and then starts over again at a stop sign, as well as a high-pitched noise that is not normal, could be caused by a few different issues. Here are a few possible causes and solutions:

1. Mass air flow sensor (MAF) - The MAF sensor may be faulty and not sending the proper signals to the engine control module (ECM), causing the engine to lose power. A mechanic will need to diagnose and replace the MAF sensor if necessary.
2. Throttle position sensor (TPS) - The TPS may be faulty and not sending the proper signals to the ECM, causing the engine to lose power. A mechanic will need to diagnose and replace the TPS if necessary.
3. Engine control module (ECM) - The ECM may be faulty and not sending the proper signals to the engine, causing the engine to lose power. A mechanic will need to diagnose and replace the ECM if necessary.
4. Exhaust system - The high-pitched noise could be caused by a problem with the exhaust system, such as a leak or blockage. A mechanic will need to diagnose and repair or replace the exhaust system as necessary.
5. Transmission - The transmission may be faulty and not shifting properly, causing the car to lose power. A mechanic will need to diagnose and repair or replace the transmission if necessary.
6. Fuel system - There could be a problem with the fuel system, such as a clogged fuel filter or a malfunctioning fuel pump. A mechanic will need to diagnose and fix the problem.

It's important to have the vehicle inspected by a qualified mechanic to diagnose the problem and perform the necessary repairs. Some of the issues can be easy to fix, but some require more extensive repairs and knowledge of the systems.

A P1776 code on your 2007 Dodge 1500 with a 4.7-liter engine indicates a problem with the transmission range sensor circuit. This sensor detects the position of the transmission shift lever and transmits a signal to the engine control module (ECM).
This information is used by the ECM to adjust the engine and transmission settings to match the selected gear. If the ECM detects a problem with the transmission range sensor circuit, the P1776 code and the check engine light will illuminate.
A faulty transmission range sensor, a damaged wiring harness, or an ECM problem are all possible causes of a P1776 code. To diagnose and repair the problem, a diagnostic test with a scanner tool and a digital voltmeter will be required.

I WOULD ADVISE that a mechanic or someone with automotive repair experience diagnose and repair this problem. Attempting to diagnose and repair the problem on your own is risky and may result in further damage to your vehicle if not done correctly.

Hi Michael, The engine check light will display fault codes when connected to a scanner or a specified bridge is made onto the diagnostic socket. It is very unusual for the ECU to be defective (but not impossible). Have a scan carried out on the vehicle and the technician (You if you are) can determine what the problem is. Regards John

you need to have the code pulled from the ecm as the light will come on if a problem has been detected by the ecm then you can start to diagnose from here in the area indicated by the code.

You will need to have your car's ECM (Computer) read by a OBD II scanner to determine what Trouble Code your ECM is giving so a mechanic can properly diagnose the problem. You can go to your local AutoZone store and they can pull the codes out of your ECM for no charge.

ay chek all the ground wires that go to the ecm
chek alterneter and battery
chek ignation module and the knock sensor
every won was good
than ay change the ecm and the problem is over

If the light does not come on when you turn the switch on but not start, more than likely the bulb is burnt out. It should come on in bulb test mode. Unfortunately you need that light to diagnose the ECM.

remove the unit from the power for one or two hours

and it will get reset