Hello,
Code 12 - possible causes:
RPM SIGNAL-NO SIGNAL TO ECU FROM DISTRIBUTOR ("Ne" OR "G")
AFTER ENGINE HAS BEEN CRANKED
--DISTRIBUTOR/CIRCUIT
--STARTERSIGNAL CIRCUIT
--IGNITER/IGNITER CIRCUIT
--ECU
As long as the timing belt did not break or jump teeth, code 12 is most likely caused by a faulty pickup inside the distributor. The distributor assembly will likely need to be replaced.
It is possible to check the resistance of the two pickup coils inside the distributor. Disconnect the electrical plug from the distributor. See diagram below.
In order from top to bottom the terminals are NE+ (red wire), NE- (blue), G- (black) and G+ (yellow). G- is grounded to the car's chassis.
Resistance between G+ and G- should be 185-275 ohm cold and 240-325 ohm engine hot.
Resistance between NE+ and NE- should be 370-550 ohm cold and 475-650 ohm hot.
Also check for shorts and continuity between the plug wires and computer.
Remove the distributor cap and check the air gap between the rotors and coils. Should be 0.008-0.016 inch.
How to check wires:
https://www.2carpros.com/articles/how-to-check-wiring
How to use a voltmeter:
https://www.2carpros.com/articles/how-to-use-a-voltmeter
Hope this helps.
Cheers, Boris
Jun 27, 2024 at 9:18 AM
