PO 401 NEW VSV shows no vacuum. EGR line off Q port attached to vacuum pump ing. on o vac. with ign. off will some time hold 15 in. when ing is turned on it looses vacuum. Replaced VSV & modulator. no changes. I have been able to find the suggested voltage @ the VSV plug. po401 (2 codes)
what should the voltage be at the EGR VSV connection on 1997 Toyota RAV4
by sophie19920 in Bath, NY on August 17, 2011
ANSWER by dandd on August 18, 2011
I would go to this link and follow this article. I wrote this as I do Emissions Diagnosis and Repair at a Gold Shield Station in Calif. A P0401 is somewhat common on Toyota and they can be stubborn to resolve. The passages have to be 'perfecto' clean. http://repairpal.com/OBD-II-Code-P0401-Toyota
replaced VSV & modulator. With EGR tube off and vacuum pump attached modulator port Q,with ing. on no reading. Sometimes I have vac. at Q when ing. is off,wnen turned on I loose Vac. I think maybe ...