'94 Camry -Check Engine Light, but no error codes

[lyonkster]

I am trying to diagnose a Check Engine light on a '94 Camry - but it does not enter the diagnostic mode when I connect E1 to T1 terminals (i.e. CEL does not start flashing). Per shop manual, I measured voltage between E1 and T1, and it is 12 volts, as it should be. Shop manual says that in this case, the ECM needs to be replaced. Is there any other test I can do before shelling out the $$$ only to find out that the ECM was not the problem?

Thanks!

[BlueFusion6851]

Buying a new/used ECU would be your only option IMHO.

[solidg]

Go to auto zone and have it tested. It should give you a code.

[imc188222]

By measuring the voltage between the two terminals and getting the result you have gotten verifies that there is nothing wrong with the wires between the connector and the ECU. This means that the problem is in the ECU. Do that test a couple of times and if you have the same result each time and the ECU still will not enter diagnostic mode when you connect the two terminals than there is no question. The ECU is bad. People mistakenly believe that when the ECU goes bad, that there car will not run. This is not always true. In my experience when the ECU goes bad the symptom is something strange like what you are experiencing or a bogus code. good luck

[lyonkster]

Originally Posted by solidg

Go to auto zone and have it tested. It should give you a code.

AutoZone here will only test OBDII systems, which this car does not have.

I checked the terminals at both connectors (under dash and engine compartment), and it won't enter the diagnostic mode when E1 and T1 are shorted at either connector. So I am pretty sure the ECM is bad.

I'll round up a used one and let you know what happens .

Thanks!