I got a code 36 today..MAF burn off...when I turn off the car, the fuel pump comes on 1 or 2 more times,(dont think it should do that)(but know the burn off should) I had to replace both and the wiring going to them, but I must have mixed them up putting them together, wanted to know what you guys think.

 

You have the classic but rare instance of the oil pressure switch "flaking out" and resetting the MAF burnoff function of the ECM along the way. Search the archives. I've posted the details about this "Impossible Code 36" a few times.

 

Thanks I will go look at it right now.

joe

 

Vader: I could not get the archives to put anything up at all, I have tryed a few times this week, at diffrent times of the day. Could you put me on a new path? I am going to keep trying.

joe

 

https://www.thirdgen.org/forums/tech...ode-36-a.html?

https://www.thirdgen.org/forums/tech...ode-36-a.html?

https://www.thirdgen.org/forums/tech...-checked.html?

And about three pages of other search results...

If the fuel pump is running intermittently after the engine is shut off, there's your hint. Disconnect the big tan wire at the oil pressure switch, insulate it so that it cannot short to ground, Clear the error codes, then drive the car normally. If the '36' code does not repeat, change your oil pressure switch. I spent a couple weeks off and on chasing one of these several years ago.

 

If it occurs again, here are some things to check:

1. The MAF Burnoff relay should have a constant 12VDC supply (battery voltage) on both the 'E' terminal and 'C' terminal (via the orange wire).
2. The 'B' terminal should switch to ground through the ECM output transistor within 20 seconds of the engine shutting off and the oil pressure switch opening. The ECM awaits the loss of power on its 'B2' terminal (Fuel Pump Voltage) before it can initiate the burn off cycle.
3. When the ECM commands a burn off cycle, the relay should close, and 12VDC is switched to both the 'D' terminal on the MAF Sensor itself, and the 'D' terminal on the MAF Power relay.
4. Power is routed through the N.C. contacts of the MAF Power relay to the MAF Sensor to enable the MAF Sensor electronics package. This is critical, since the MAF Sensor must report a signal back to the ECM to prove a good burn off cycle. This is also why a failing MAF Power relay can cause a MAF Burnoff error.
5. Upon receiving all these signals, the MAF Sensor hot wire is heated to full incandescence, and the MAF Sensor reads the hot wire current at full. This causes the MAF Sensor to report a full, 5VDC saturated (non-duty-cycling) signal to the ECM.
6. Upon receipt of this signal, the ECM registers a complete MAF burn off cycle, ungrounds the 'B' terminal of the MAF Burnoff relay, and is satisfied.

NOTE: Any interruption of the cycle will cause an error, and subsequent error code. This includes marginal relay contacts, poor connections and grounds at any point, and intermittent operation of the auxilliary oil pressure switch, since any voltage from the oil pressure switch will indicate to the ECM that the engine is not shut down, effectively terminating the cycle.



Other things to check:

1. The MAF Power relay should have a constant 12VDC supply (battery voltage) on the 'A' terminal (via the orange wire).
2. There should be a 12VDC supply whenever the ignition is ON at the 'B' terminal (via the blk/pnk wire).
3. The 'E' terminal should have a good ground at all times through the blk/wht wire.
4. Both the normally closed and normally open contacts of the relay (from terminals 'E' to 'A' for N.O., and 'D' to 'A' for N.C.) must be operational and reliable (see above).

Hope that helps.