Deathbarel

I have a check engine light on. the ight is always on when the rpms are below 4k. above that the light is off. i have an ecu master stand alone in the car. when i jump the pins to get the light to flash it does not flash the code. the standalone says there are no check engine problems. what other modules can make the light come on?

Arsenii

Hello,

How is the CEL wired to the cluster?
Do you have any other issues with the instrument cluster?

Any ECU I know of should output the information on whether the CEL light itself is currently on or off, see if your standalone unit has something like that, that is, if the CEL is wired to that standalone. If the diagnostics show that the light is supposed to be off when it is on, there is an issue with the cluster, which is somewhat common for those cars. If the CEL is reported on, there is an issue with the ECU or the way CEL is wired, you will have to contact the ECU manufacturer for more details.

Hope this helps and best of luck!

Deathbarel

the CEL is unchanged from factory wiring.
the rpm and speedo dont work

the ecu does output a CEL, it say there is nothing.

youre saying wire the CEL to an output on the ECU? thats seems like a smart thing!

Arsenii

Do they not work because they are not wired in or because there is some kind of malfunction with the cluster? If the car runs but doesn't display RPM, it can only be either an ECU, wiring or the cluster. There was a common issue with those clusters failing over time, so I wonder if that could be part of your problem. Also check that you get speed readouts in Engine Live Parameters.

Not sure I followed on that, do you mean that you can activate a CEL with a Diagnostics tool? What I meant by my previous post is that OBD2 diagnostics equipment usually has a separate parameter in Engine Live Data, which specifies if the ECU is actually commanding the CEL to be on at the moment, which can be useful if you don't have a light in the cluster for example, or cases like the one you ran into.

You have a 1992 model year, which came before OBD2 came in, so if your standalone ECU supports it, you can add a low power LED bulb between B+ and W pins, which will give you a duplicate CEL, it can help bypass the cluster from the list.

CEL is already wired straight to the ECU, if you haven't done anything to the wiring, there is no need to make any changes.

Hope this helps and best of luck!

Deathbarel

the clusters are wired in correctly, they used to work but are old now.

the aftermarket ecu is the one who outputs a cel whether its there or not, the ecu said there are no problems, but the light is on

the problem was in the base map, the ecu was literally telling the cel to be on because below 4k rpm and because this input 4 is below 300 mv, nothing is mapped to that input. these were the base map settings. i changed the input parameter to be "Check Engine Code" greater/equal to 1 and rpm below 300(engine off).

thank you for helping me think differently, it lead me to finding the real problem. i very much appreciate it.