Q: does my key have to be programmed to new ecm

asked by on

I think my ECM is bad..code p705 and p0302 read w scanner multiple times. Had diagnostics ran at dealership, was told faulty neutral safety switch (transmission range sensor) and coil not plug on cylinder2. I've replaced sensor and coil and wiped codes from memory and now codes still present along with p0110 p0100 p0101 now. Dealership rule outs for p705 were the sensor and the ecm...my car doesn't seem 2 kno what gear it's in and it's mimicking transmission issues...if I get a new ecm do I have to program my key to it or will it need the same type of chip that's already in my key?...and is a ecm a reasonable culprit for my issues?

There is a long, long decision tree in the Factory Service Manual (FSM) to deal with issues like the one you have and it is only at the very end of that tree, that you consider ECM failure. Indeed, ECM failures are so rare that half of all ECM’s returned to re-builders as "warranty exchanges" are in fact perfectly good. If ECM failure is suspected, if you are working with a Toyota dealership all they have to do is swap in a known good ECM to rule that component in or out. They could also first try re-flashing your ECM (that’s easy).


The point is there is a lot to rule out and in your case you have several powertrain codes available, that if tracked down and resolved, could resolve the symptoms you are having. What I suggest is you request a check engine light diagnostic. A certified mechanic from YourMechanic would track down the causes of the three codes you have cited and first get that resolved. If problems continue, the mechanic would just simply follow the remainder of the decision tree in the FSM until this is resolved. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. does my key have to be programmed to new ecm

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: I have a 2007 Toyota Prius. I was driving last night and the master warning light came on.

Hi There, The master warning light in the hybrids generally refers to the hybrid battery control module. This module monitors the charging of the high voltage battery (main hybrid battery) in these vehicles. When this control module is not working...

Q: oil light on, loud and noisy while idling, what does this mean?

Hi there: Although it's very hard to tell remotely without physically inspecting your Toyota, I don't believe the oil indicator light and the thumping noise are related. It's possible that your front wheel bearings are what is causing the repeated...

Q: How long does it take to replace the compressor bracket

Once the compressor is removed from the bracket, then there is only a couple of bolts that hold the bracket to the engine block. Make sure the compressor rear bracket is tightened or the new bracket will break. The bracket...

Related articles

How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...