92 ram50 issues

[boon]

I have a 92 ram50 with 2.4l. Its been running good til the other morning wouldnt hardly start and the check engine light came on. codes 13,15,21,25 came up. Why would all the code come at once? ECM went bad? Still runs smooth just really hard starting when cold. It use to have high idle when started but now it dont. ohmed the sensors and couldnt find a bad one. Any Ideas
Thanks

[pennyman1]

possible bad MAF, moisture in connectors, or caps bad in ECM. What are the codes for?

[boon]

intake air temp sensor, idle speed control motor position sensor, engine coolant temp sensor, barometric press sensor.

[boon]

before I could unhook battery and erase codes now cant

[muddracer]

Its possible there could be a bad ground that they share but would have to check a wiring diagram to see

[boon]

I will look it up and see

[DroppedMitsu]

Change the coolant temp sensor first. One guy had the craziest problems with his truck running funny/rough and he changed MAF and ECU and TPS and it ended up being the temp sensor. That one tells the ECU what temp the engine is at and the ecu calculates how much fuel to give, I guess when they go bad they tell the engine to go super rich and causes issues. If not then I'd try the MAF next since it is throwing 2 codes related to it.

[Jeff V.]

I'd make sure the grounds for all those things are good, and also that they're each getting the 12V they need. Should be easy enough to test with a multimeter.

[boon]

Yep, the first thing I changed was the coolant sensor since it is the cheapest. No change. I think I will start checking all sensors at the computer before I spend 100 on a map sensor. I pulled the Idle speed control motor and sensor since it was one of the codes and the motor moved like it is suppose to but the ohm didnt change on the sensor like the book said and when I looked up the part it said not avail. Not sure if that affects it or not , but I bet its the map, air temp, baram air flow box.
Thanks

[boon]

UPDATE!!! I took the ECM or computer in to a local guy and he said he has done 1000 of them, not so many now since there isnt many ram 50s out there. Natorious for goin bad. Cost 175 but everything works great and no check engine light.

[Can1991Ram]

was it the caps that went bad?

[KCKC Amy]

so, what did he do? replace the whole ecm or rebuild the existing one?

[geezer101]

so, what did he do? replace the whole ecm or rebuild the existing one?


They replace the bad caps in them and if the caps have eaten tracks off the board, they run bridges on them to complete the circuits. If you are game and can get the values off the capacitors, you can DIY this job (also eyeball the board for dry soldered joints and touch them up...)