1994 Camry I4 fault code 12

JMART116

MEMBER
1994 TOYOTA CAMRY

1994 Camry Japan, I4, 5SFE, automatic, 165,000 diagnostic code 12, No RPM signal. Car seems to run fine except every now and then the car will misfire and check engine light will go ON. Car will then apparently correct itself because the check engine light will go OFF. Idles fine except once in a while it will misfire. Not predictable. It only stalled on me once but started right up. Hopefully not a sign of future problems. Entire distributor assembly completely replaced 4 years ago, replaced fuel pump & filter 4 years ago. New wires, plugs, rotor last month. Still has original ignitor and ALL original senors. Not sure when to replace sensors. Do you wait to get a fault code for a particular sensor then replace? Has been a great car. My fault code 12 is my problem right now. Any thoughts? Thanks

1 Reply

MHPAUTOS

MECHANIC
31,937 POSTS

Hi there,

Step 1 Check for aprox 0.75 V at each terminal of the distributor harness plug. (Distrubitor harness plug)

2. If voltage is not correct, check the wiring for continuity and shorts to earth between Dist & ECU. If no fault found replace ECU.

3. Check the resistance of the distributor pick up coils, if not correct replace distributor.

4. Check the air gap between the signal rotor and the pick up coil, if not correct replace distributor.

This may be a bit to much for you to do, if so have a mechanic do it for you.

Good luck,

Mark (mhpautos)