02 Sentra Service Engine Soon light

[PacoBJuarez]

Well, three days after I installed the throttle body spacer and crank pulley, my SES light has now come on. This is the code:

p0507

The PCM has determined that the engine RPM is higher than expected for the current engine operating conditions.

Definition: IAC circuit condition or idle speed higher/lower than expected

Explanation: The ECM has detected that the IAC counts are higher or lower than expected. The engine speed is not in its expected range.

Probable causes:1. Vacuum leak on engine2. Dirty throttle body3. IAC motor defective4. Poor electrical connection to the IAC valve

Um... what do I do? Might the throttle body spacer have something to do with this? Or do I have a problem?

[gotak]

Since a TBS does jack all to sequential port injected engines... I'll say more likely your pulley.

[nametakennow]

Is your idle high? It may need to be adjusted.

Otherwise you best bet is the TPS.

The pulley may be causing it, but an idle adjustment should compensate. Search for it, I know someone posted how to do it on a Spec awhile back (you may have to try archived threads).

[D3stro]

Maybe just an idle fuel relearn should be alright to erase that SES code.

[PacoBJuarez]

Is your idle high? It may need to be adjusted.

Otherwise you best bet is the TPS.

The pulley may be causing it, but an idle adjustment should compensate. Search for it, I know someone posted how to do it on a Spec awhile back (you may have to try archived threads).

My idle is around 2k for like 2 or 3 seconds, and then it drops down to normal. That started happening after I installed the TBS and the crank pulley. Is it easy to adjust the idle? And would that actually make the SES light turn off?

[PacoBJuarez]

Maybe just an idle fuel relearn should be alright to erase that SES code.

And what is that?

[nametakennow]

Idle RelearnBASIC SERVICE PROCEDURE- Turn ignition switch OFF and wait at least 10 seconds.- Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.- Repeat the following procedure quickly five times within 5 seconds.a. Fully depress the accelerator pedal.b. Fully release the accelerator pedal.- Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stopsblinking and turned ON.- Fully release the accelerator pedal within 3 seconds after the MIL goes off.- Start engine and let it idle.- Wait 20 seconds.- Rev up the engine two or three times and make sure that idle speed and ignition timing are within thespecifications.

[PacoBJuarez]

Thanks nametakennow! I will try that soon and post if it helped or not.

[nachtfrau]

I recently just replaced my idler pulley ($52 from the dealer) AFTER trying to pin-point a rough idle issue. Before replacing the pulley, I replaced the MAF, the Throttle body assembly (can't get just the TPS, need to buy the whole assembly for the SE-R's), and my belt. Turns out it was just the pulley!

Ya I'm pissed needless to say, spent $300 for the MAF, $350 for the throttle body assembly, and $25 for the belt. So if I were you I'd start with the cheapest possible, Belt/Pulley

The Idle re-learn is simple to do, just make sure you follow the instructions to the T! Goodluck!

[PacoBJuarez]

2 questions: what do MAF and MIL mean?

[nametakennow]

MIL = CEL = SES

Malfunction Indicator Light

MAF = Mass AirFlow sensor

[PacoBJuarez]

Well, I followed the instructions and definitely didn't see the CEL light blink at all.

[nametakennow]

The procedure is practically straight out of the FSM, so try it again or find an OBDII scanner.

[PacoBJuarez]

What the heck is an OBDII scanner?

[nametakennow]

It's what the emissions people use in handheld form. You plug it into the OBDII port and it reads the codes. Decent ones with an on-board explanation of the code or at least a code book run ~$100 last I checked, though you may be able to find a little bit cheaper model.

OBDII = OnBoard Diagnostic II, all vehicles as of '96 were required to have this testing system. I think we're on the cusp of the changeover to OBDIII now.

OBDII is handy because it means there's no sniffer, so it streamlines the emissions testing process. At the same time, it makes it easier for people to do their own diagnosis with the proper equipment.

The port is on the driver's side under the dash. The car must either be running or in the "on" position of the key (i.e. the position where you hear the fuel pump turn on, all the lights on the dash come on, and the car makes a few annoying bink noises) for codes to be read.