Check Engine Light - Can't read with Tool, Can't get to flash, can't get to clear

Wereknight

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What would cause the check engine light to stay on and not be able to clear?

I have an '85 Fiero 2m4 4cyl. 2.5L Car starts just fine, but the check engine light will not go away, flash the codes, or be read by Auto-Zone's reader.

I've tried the following:
1. took car to 2 different parts stores and a mechanic, none of them could get the reader to read the codes

2. Tried using the manual code retrieval method of grounding the pins ALDL port next to the cigar lighter in the center console and switching the key to "on" - no flashing of codes, just stayed on constantly

3. Tried clearing the code memory by:
1) removing ECM fuse for 20 seconds (Chilton Manual reccomended 10 seconds),
2) removing all fuses and leaving them out for 2 min,
3) disconnecting positive battery cable for 5 min,
4) disconnecting both positive and negative battery cables for 30 min, turning the key to start while it was disconnected (to clear any residual system power).​

After each of the attempts to clear the ECM memory I started the car and the check engine light never blinked or anything, just always stays lit.

Could this be caused by a bad ECM? is there a trick or something I'm missing that might otherwise work? Could it be just a bad ALDL?

Thanks in advance for any help you can provide.

~Wereknight
 
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you need a shop that can read OBDI not OBDII. When you pulled those fuses, did you check if any of them were blown?
 
Thanks for your response. Yes, all three used an OBDI, and no fuses were blown.
 
The 85 2.5 Fiero uses the 1226864 ECM. For that ECM to be scanned it needs the B connector of the ALDL to be connected to a 10K ohm resistor. That is also the terminal that needs to be grounded for the codes to flash. Since both of these functions are failing I suspect that the terminal is corroded to the point that it is not making contact. Unbolt the ALDL connector and take a look at the terminal. The wire will be a White/Black wire. The terminal can be backed out of the connector by first taking out the secondary terminal retention clip (white plastic) and then untanging the metal terminal with a small screwdriver. That wire can be simply grounded to get the ECM to flash the error codes.

Also I do sell an OBD1 cable that works with laptops however since it seems like your B terminal isn't working I would expect the cable also will fail.

http://reddevilriver.com/aldl.html
 
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