MAF Connector Wiring

[Amybirds]

Yes, it appears I have a TCS ecu on a non-TCS car. A number of folks had given me the impression that would be ok, just not the other way around… Are you saying that it's going to not work properly, and if so, will you explain what happens? Thanks,-Amy

[elwesso]

It will work fine, my car doesnt have TCS but it has a TCS ECU, and its ran fine for YEARS!!!!!

It will just throw a code and it will be fine..... Dont worry about it.

Dont worry about 2nd TPS, we need to see why the CAS is throwing a code.. Dont worry about the TCU code yet, we'll get to that eventually.....

Go through and do the dignostic procedure on the CAS.

[Amybirds]

Thanks Wes!!! Thats' exactly what I wanted to hear! I'm going to tackle the CAS diagnostics tonight (I hope) and I'll let you know...-Amy

[maxnix]

It will just throw a code and it will be fine..... Dont worry about it.

Doesn't that mean the CEL is constantly illuminated?

Not fatal, but disconcerting not to know if there is a real failure or not.

[elwesso]

NO, 2nd TPS doesnt throw a CEL.

[Amybirds]

Well, after doing the diagnostics for the CAS and finding nothing amiss, we discovered we didn't have the ECU harness screwed in tightly enough (which was made evident by the fact that when we tilted the ECU it would act like it was getting a connection, relays clicking, etc, but when we untilted it it would seem to not be connected). So we screwed it in tighter and YAY(!) the car starts!!!! But then dies.

But that's a heck of a lot further than we've been in nearly a month!!

My current error codes on the ECU are 12 (MAF) and 46 (Secondary Throttle Sensor). I know I can disregard the Secondary Throttle Sensor since I don't have a secondary throttle. And the MAF code likely means that we fried the MAF during our foolish trial and error (emphasis on error) wiring to it. Just to be sure though, we've triple checked all the wiring to the MAF connector to make sure that's no longer an issue. It's wired correctly with power and continuity as appropriate.

I'm in the process of getting another MAF to replace the fried one and will post the results once I get it.

-Amy

[elwesso]

I would try unplugging the MAF and see if it starts..... It should run without the MAF, just not very good.

[Amybirds]

I started the car with the MAF unplugged. Car starts up and seems fine but I didn't try driving it. I then plugged the MAF back in and started it up. Car started fine but then the RPMs slowly go down till it dies; if you give it more and more gas it keeps it "alive" longer but it still dies (and then the engine is flooded).

Think it's a bad MAF?

[Amybirds]

YAY!!! The car is up and running again! The only error code we get is for the Secondary Throttle position sensor which is because the ECU has that feature and our car does not. Hooray!!!!

A BIG thank you to all of you for your help and suggestions along the way--we would have been very lost without you. It is much appreciated!-Amy

Here's a quick synopsis of our symptoms and solutions for anyone searching the threads...

FRIED ECU:cause -- snipping all three MAF wires at the same time with the key/ignition in the "on" positionsymptoms -- blew Engine Cont fuse in engine compartment; no ECU error codes; ECCS relay, ignition control relay, EGRC solenoid valve all making a rhythmic clicking (ticking) noise over and over when the key was turned to "on"; fuel pump continuously operating when key on (instead of turning off after about 5 seconds); car wouldn't start (engine was turning over)solution -- replaced ECU with a new (used) one

FRIED MAF:cause -- miswiring the MAF (correct wiring is W towards fender, B in middle, B/W towards engine)symptoms -- car started fine with the MAF disconnected (once we replaced our fried ECU, see above), but would lose RPM after starting when connected; trouble code 12 on the ECUsolution -- replaced MAFS with a new (used) one

[maxnix]

Great going!

Even How-Not-To is worthwhile of a writeup.

Experience is education gained dearly.
Modified by maxnix at 7:59 AM 8/29/2006

[1990Q45'r]

Excellent!

[bullittandy]

Its inspiring to hear of a success story. Everything I've learned about cars I learned it this way-by screwing it up first. I restored a 1955 Chevy from the ground up this way. People would ask me- "How did you know how to restore it?""By doing it wrong first."

[Q451990]

Nice to hear this all worked out nicely in the end!

Heath