# troubleshooting failed throttle relearn



## kitand (Mar 20, 2020)

2007 Versa S.
After replacing valve cover gasket, replacing coils/plugs, cleaning throttle body, and replacing PCV valve, I have high revs on idle or neutral and the throttle relearn procedure fails (CEL won't turn steady in last step).
Yes, it COULD be a vacuum leak. Or it COULD be the electronic throttle control.
Do any of these below symptoms help pinpoint either of these possibilities?

high revs on idle or neutral (close to 2K) and after some warmup there is pulsating idle (maybe 2.3K to 1.5K repeatedly).
when in drive, when braked the revs are somewhat lower and do not pulsate. Car is still somewhat drivable but at high base revs.
driving engine operation is smooth, not clunky, so it doesn't seem like it's just a one-cylinder problem.
the only trouble code is P0507 (idle air control system), no others.
have already repeatedly tried the throttle relearn procedure a few times, with engine properly warmed, but the CEL never turns solid (never stops flashing) like it should in the last step.

So far I've tried finding vacuum leak with the brake cleaner technique, and could not detect any idle change, but it's hard to reach back of throttle body and most areas around the valve cover gasket on this car.


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## rogoman (Dec 16, 2004)

Before performing Idle Air Volume Learning, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
● Battery voltage: More than 12.9V (At idle)
● Engine coolant temperature: 70 - 95°C (158 - 203°F)
● Park/neutral position (PNP) switch: ON
● Electric load switch: OFF
[Air conditioner, headlamp, rear window defogger]
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine
is started the headlamp will not be illuminated.
● Steering wheel: Neutral (Straight-ahead position)
● Vehicle speed: Stopped
● Transmission: Warmed-up

To do the relearn, these have to be performed:
1. Perform EC-77, "Accelerator Pedal Released Position Learning" .
2. Perform EC-78, "Throttle Valve Closed Position Learning" .
5. Perform EC-78, "Idle Air Volume Learning" .

The above procedures can be found in the *FSM* for your vehicle.

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To check the intake system for a vacuum leak, attach a *vacuum gauge* to a full vacuum source. With the engine fully warmed up, the reading at idle should be 18 - 20 InHg. At 3,000 RPM, it should be 21 InHg. If readings are under 18 InHg, check the intake manifold nuts to make sure they are tight. The gasket may have failed; spray a water mist at the gasket to see if the gauge reading changes. Also check the intake plenum bellows at the throttle valve and at the MAF for cracks or loose clamps.


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## kitand (Mar 20, 2020)

Thanks Rogoman. I already had tried the relearn procedure (with warming up, etc) a few times with no luck. There are variations of it posted online, and here below I've posted the variation that worked for me in the end. It involves putting the car in Drive relatively soon after starting it in Park (see below). Also, I've tacke on an easy procedure to make the Check Engine Light disappear after the process is done. I've read that it can eventually disappear itself, but this expedited it.

CONDITIONS: Check Engine Light (CEL) with P0507 trouble code and high/pulsating idle, after disconnecting and reconnecting electrical to throttle position controller such as when cleaning throttle body.

TOOLS NEEDED: stopwatch or timer showing seconds.

1. When engine COLD, first perform the Accelerator Released Position and then the Throttle Valve Closed Position procedure.

2. Warm up engine at this point. I drove around my neighborhood for a bit less than 10 minutes despite somewhat high base revs in drive.

3. Car in Park, turn off all electrical powered stuff, wheels turned straight.

4. Turn key OFF and wait at least 10 seconds.

5. Turn key ON (not ignition) and start stopwatch at same time.

6. When stopwatch is at 3 seconds, press & release accelerator pedal 5x hard and quickly.

7. When stopwatch is at 15 seconds, press accelerator pedal and keep it down.

8. Approx when stopwatch shows 27 seconds, the solid CEL goes out then starts blinking. Keep the accelerator down. If the CEL never starts blinking, then something is not working and you'd better start over again.

9. When the CEL becomes solid again (stops blinking) about 10 seconds later, immediately start the engine and let it idle. It will still likely be a high-rev/pulsating idle.

10. Let it run for about 20 seconds and rev the gas a few times.

11. With foot on brake, shift into Drive. Idle will now go WAY down under 1000rpm. Shift to Park again, and the car will find its regular idle speed, and purr like a rather quiet kitten again. Operation will be normal except CEL will still be on. It may disappear soon on its own, or you can do the following:



EASY RESET OF CHECK ENGINE LIGHT (CEL)

1. Turn key OFF and wait at least 10 seconds

2. Turn key ON (no ignition), wait 3 seconds, then press & release accelerator 5x hard and quickly.

3. Wait 10 seconds, then fully press accelerator.

4. After about 12 seconds CEL will go off then start blinking. As soon as it starts blinking, release the accelerator.

5. Wait 10 seconds, then fully press accelerator again.

6. Wait 10 seconds, then release the accelerator again.

7. Turn the key to off, then immediately start the engine. The CEL should be gone now.


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