Toyota Repair: check engine light, egr vacuum modulator, egr valve

Question
QUESTION: Hi Ted,

I have a 2000 Rav4, just under 105,000 miles.  The other day the check engine light came on.  A day and a half later it went back off.  I thought the only way the light went off was you had to disconnect the negetive battery cable for a few minutes, or with a scan tool.  What would cause the light to go off?
I did get the code though with an OBD II.  PO401 Exhaust gas circulation flow insufficient detected.  I first tried to get the code by jumping TE1-E1 and ignition in the "on" position, but the check engine light never flashed it just remained on.

Thanks,

Rick

ANSWER: In most cases this code is set because there is insufficient exhaust gas recirculation, this is almost always caused by the egr modulator valve, it's mounted directly on the egr valve, replacing it and also the egr vsv( vacuum switching valve) solves this problem, the vsv is located below the intake manifold and has two vacuum hoses connected to it coming from the modulator valve.

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QUESTION: Does the code have to be cleared once the parts have been changed?  If so, how, by disconnecting the negitive battery cable for a few minutes, or ?
Is the egr modulator valve the same as the egr vacuum modulator?  If so, mine is next the egr valve
I have read about getting the code by jumping the terminals TE1-E1, and ingition "on".  Why did this not work?

Thanks,

Rick

Answer
The code has to be cleared by either removing the neg battery terminal or the 15A EFI fuse. Yes the valves are the same, it's attached to a bracket on the intake chamber, the codes should be able to be read by connecting between TE1+E1, make sure the jumper is making contact with the small meta strip in the connector, it's easy to miss the connector.