Good afternoon. This post will be long but worth the read. My Tracker will turn over but it will not start. I have pulled every fuse and they are all good. Symptoms are as follows:

1) When I turn the key to the run position the fuel pump does not engage. I hear no noise coming from the fuel pump at all. I'm pretty handy so I replaced the fuel pump and fuel strainer....no change.

2) When I turn the key to the run position three lights illuminate on the dash: Air Bag, Brake, and the battery symbol. Sometimes the Air Bag light will flash for a few seconds and then stay on. None of the lights go out. The fuel tank is full and the fuel gauge moves over to full right away.

3) With the key in run the following lights and warnings do NOT come on: Service Engine Soon, the Oil symbol, and the Fasten Seat Belt symbol. I'm pretty sure these lights are supposed to come on every time you put the key in the run/on position.

4) I hooked up a scanner to pull the codes and the scanner failed to communicate with the car. I've used this scanner successfully on other cars I own. I was able to program the year, make, and model into the scanner and it still would not connect.

This is the 2WD base model with manual everything so the 4WD and ABS warnings are not an issue.

I pulled the computer out from under the glove compartment, opened it up, and saw no obvious damage. It's a fairly modern board. I'm a trained electronics maintenance guy but the equipment I have on hand will not tell me if the board is good or bad, and I don't know anyone or any company that can diagnose and repair these. Does anyone know which pins the board gets power from?

Do any of these symptoms point to a bad computer board?

Thanks

 

Based on the model year I am assuming you have the 2.0 liter engine. I only have schematics for the 2001 Tracker but they should be close enough to give you a general idea of what's going on. I will attempt to address your concerns point by point.

1. The fuel pump is controlled by the fuel pump relay. The fuel pump relay is controlled by the PCM. Either could be at fault.

2. The Air Bag light will flash seven times during its self-test. This is normal. The Air Bag, Brake and Battery charge lights get their inputs directly from the sending units. They have no connection to the PCM. The fuel level signal goes to both the gauge and the PCM but the fuel gauge will still work even if the PCM does not read the data.

3. These are the instrument lights that illuminate on my Tracker with Key On Engine Off (KOEO)



Service Engine Soon (or MIL) is driven by the PCM and should be illuminated KOEO. The Oil symbol, Battery and Fasten Seat Belt symbols are not driven by the PCM.

4. The scanner failing to communicate with the PCM is a bad sign. But try another scanner before you replace the PCM. Also, be aware a replacement PCM may have to be programmed after it's installed.

Since you are an electronics tech I am providing the pinouts for a 2001 Tracker/Vitara PCM.

 

Fuel pump relay?

 

You asked about the PCM power pins. From the documentation above:

Grounds are found at pins:
C51-3-6
C51-3-17
C51-2-28

+12 VDC is found at pins;
C51-3-15
C51-3-20
and through the Main Relay (item22)
C51-3-4

I found it interesting that the Main Relay feeds +12 VDC to both the
Fuel Pump Relay and the PCM power pins --- the two circuits that are not working for you.
It may just be coincidence but it might be worth checking out.



The Main Relay is one of the relays on junction panel to the left of your left foot. On my
Tracker the Fuel Pump Relay is directly below the Main Relay.

 

So I took some advice and pulled the main relay and the fuel pump relay. I swapped their positions and put them back in...BOOM the car fired right up.

 

That's cool. Does the scanner recognize the PCM now? What is the status of the MIL (Service engine soon) light KOEO?

 

The car would not start again yesterday so I replaced both relays. The scanner recognizes the PCM and the MIL light KOEO works...and it starts right up.

 

I love a happy ending. Thanks for the follow-up post.