12-Step A, Fuel Control Circuit (Code 27)

Need a step-by-step guide?

Get an AI-powered repair guide with parts lists, cost estimates, and clear instructions for your 1985 Plymouth.

AI Repair Guides

1. With diagnostic read-out tool connected to engine test connector, place ignition switch in the Off position.
2. Disconnect fuel injector electrical connector.
3. Connect a voltmeter between terminals of fuel injector electrical connector.
4. Disconnect logic module white electrical connector.
5. Connect a jumper wire between logic module white electrical connector terminal No. 2 and ground.
6. Place ignition switch in the RUN position, then depress diagnostic read-out tool ATM button and note voltmeter reading.
7. If voltmeter indicates voltage, replace logic module. If voltmeter indicates a negative voltage reading, reverse voltmeter leads and repeat test.
CAUTION: Before replacing the logic module make sure the terminal in cavity No. 2 is not crushed so that it cannot touch the logic module pin.
8. If voltmeter indicates no voltage, proceed to Test 12 step B.





← Back to With Single Point Fuel Injection (SPI)All Makes