Hello ladies and gents,
I've been working on the above van with an engine code 4WZ-FTV being a 2.0 litre diesel. I read fault codes P0437 and P1499 both referring to the air metering valve operation. Reading live data I found that the desired percentage for the air mixure unit as Toyota call it (air metering valve) showed 0% and the actual live reading percentage also being 0% at idle. Nothing changes during rapid acceleration (WOT) or deceleration. I went into component test measures and found that a test can be performed and after doing so I was no better off as the scanner told me nothing. I decided to remove it and do a visual inspection and when I did I found the vacuum capsule linkage had broken, and the throttle plate is in the fully open position this being the nominal position for this air mixure unit. After finding this linkage problem I did a temporary repair and tried the operation again only to find the same results, however this time when I shut the engine off the vacuum was then created to about 20 inHg for about 2 seconds or so which closed the throttle plate and then the vacuum discharged and the throttle plate fully opened again.
Even Toyota on their trade site don't seem to provide any detailed information as I can find to explain how this vacuum system works!
Anyone got any experience with these systems and know how the vacuum system functions normally?
Hi Technician I dont know that particular system normal diesel protocol is the throttle valve is only used for egr feathering and engine shut off,when the engine shuts down the throttle closes to cut air supply to lessen engine judder then reopens, when egr is operative the valve is controlled to create a slight vacuum to draw exhaust gasses through, try your live data when egr is commanded. Cheers Ron
Got another question about Toyota also previously seen in this PCM memories. A code 0303 BSI redo configuration - Not characterized - Local.
I have carried out previously the BSI reset procedure following the instructions from the scanner, and I must say I didn't think the instructions were brilliant as I was not sure of the end results as the scanner instructions didn't make them clear. The code cleared and did not immediately return, but after a 30 miles road trip the code 0303 returned. I've also searched the Toyota tech site for this code but nothing I can find listed, has anyone come across this code and after the BSI reset, does it look like a BSI fault?
Yeah I found that code in different places several times, but specific 0303 nothing. Going to leave it for now and see if anything rears its head in the fault world from it, it not I'd assume it won't be anything to worry about. I have not noticed any drive ability problems and the battery/charging system seems to be working OK.
Not really Pico related but the Toyota Proace is ultimately a Peugeot Expert van underneath and the 4WZ engine is PSA derived.
If you're looking for these specific fault codes you may have better luck looking on the PSA technical information website and manually searching for the correct model of van.