Help with wiring

sharkrc

My brother is having issues with his temperture guage as it pegs on start up. At the same time it kills the odometer-speedometer. While going thru trying to locate the ECT sensor which we finally found on back of engine. 2.5 L I believe is what he has. Anyway for about 15 minutes we got it all working again, so leads me to believe what ever wire is causing it is shorting out somewhere. If you take the plug off the ECT it does not peg but the odometer/speed still doesn't work. Can anyone point me in the right direction of the wires that could effect these items. Thanks.

stever

Not really, but I can point you in the direction for free wiring schematics at bbbind.com.

sharkrc

Its a start would be happy to get wiring diagrams. I downloaded a manual for grand vitara but it doesn't even show the ECT on back of the engine. I just need to locate where they all tie together and work on one at a time. Thanks for the help.

thecardoc3

The coolant gage does not have its own temperature sensor. It uses the PCM's coolant temperature sensor information as shared on the communication data bus. The instrument panel controller takes that digital information and commands the gage to display the temperature.

You need a scan tool that can access both the PCM as well as the instrument cluster. The tool must be able to display the data being generated by them as well as what is used by them to control the outputs. You also must have bi-directional controls to over-ride the system for testing. With a full function scan tool you can check and see what temperature the PCM believes the engine is at and from there determine if the instrument cluster is commanding the gage to work accordingly. The fact that you also have a speedometer issue makes an instrument cluster issue very likely.

sharkrc

tried a used instrument cluster and had exact same results. Since I dont have a scan tool. And my brother is on a fixed income, guess he will just have to drive it till it dies. Thanks for the info.