When you replace your 2001, 2002 or 2003 Toyota RAV4 ECM (car computer or engine computer) with an used unit, either bought at eBay or at a salvage yard, junker, etc., if your vehicle is equipped with an immobilizer system, which is an anti-theft security system, you must either reprogram the ecm to work with your existing keys, or buy new keys, which must be cut and programmed for matching the ECM unit you just purchased.

In this article, we will cover the part where the ECM is reprogrammed, as that is the easier way, and will use as an example the 89661-42820 RAV4 ECM. That part number is to mention just one, as this procedure will cover all 2001 – 2003 models, either 4×2 or 4×4 wheel drive.

For reprogramming, if you …read full article

Sometimes when working with immobilizer EEPROMs, the ideal way of programming the EEPROM is by doing it while it is in the circuit, as removing it, programming and resoldering it back to the circuit, adds a bit more of effort to complete the job.

Doing it “in-circuit” can be accomplished by using the SOIC-8 clip, connecting it over the EEPROM chip while it is in circuit, but sometimes, some inconveniences are present. Some of those inconveniences are; the need of cleaning the EEPROM leads from any protecting coating the ECM might have, or the fact that the EEPROM in question might have a too low profile, making it impossible to keep the clip in place, or the situation that we will cover here; the ECM circuit is too sensitive to the voltage that the EEPROM programmer injects to it, for working (reading/writing) with the EEPROM. In this case, the problem is that the micro controller of the ECM is attempting to start (run) with the reading supplied voltage. Of course, thus will vary from ECM to ECM and from programmer to programmer.

The solution for this situation is …read full article

If you own a 2001, 2002 or 2003 Toyota RAV4 vehicle and you are having problems with the automatic transmission, which symptoms are harsh shifting, loss of power, launching on second or third gear and/or hard engagement when it is put in reverse, then you should know that those problems are caused by a defective engine computer, which also controls the automatic transmission.

These problems are erratic and may only show at intermittent intervals or when the vehicle is warm or have been driven for a specific time. Sometimes it happens one day and the next morning it does not show.

When the computer (ecm or ecu) is defective, it will …read full article

Quick and easy solution for curing the annoying hesitation, jittering, lag back feeling, stalling or whatever you wish to call it, which happens when you are accelerating your car.

(Note: While this article is dedicated to the Toyota Corolla late models, this will apply to most cars equipped with a MAF or flow meter sensor, either from Toyota or any other brand, like Nissan, Mitsubishi, etc.)

If you own a 2004, 2005, 2006 or 2007 Toyota Corolla and your car hesitates when you accelerate or it hesitates when driving, you should try the solution described here. Below is a list of the behavior your car may show that tells that you should try this procedure before going to a mechanic or repair shop.

• The accelerator is slightly pressed while the car is running and it slightly jitters or hesitates
• After completely stopping the car (a red light for example), it hesitates when you accelerate to continue driving
• Engine power is below the usual level
• Sometimes check engine light turns on

You should know that while those problems can be …read full article