passing inspection with EV monitor not in ready state?

Could you post a photo of the "EV" that is blinking?

Tell us more about the 'scanner' make and model.

Bob Wilson

 

I downloaded and read the manual. It looks like it only addresses 'generic' codes and none of the NHW11 Prius specific codes. There are a bunch of Prius specific codes that unit won't be able to read.

I'm still curious about the "EV" error. Can you identify where this error code showed up?

I downloaded the owner's manual and these are the pages covering the error displays. If we can figure out what "EV" is, we'll have something currently unknown.

Here are the various error codes:



Thanks,
Bob Wilson

 

Thanks!

So the "EV" is from the scanner, not the car. I'll download the manual later today and see what this is supposed to be about. However, I suspect it stands from "EvaporatiVe system" and is part of the emissions control system. But to answer your question:

• It will not pass.

The Prius like all modern cars, has a charcoal canister that is supposed to trap gasoline fumes when you fill up. Then as you drive down the road and the engine is running, a valve opens up to draw off the gasoline fumes. It sounds as if one or more parts of that system are stuck or failed or otherwise detected by the car.

If you will check Google, "P1437 prius," you'll get a lot of useful posting about what folks found when that happened to their cars. Sad to say, there are often more than one potential cause so I can't guess what might have failed. But one thing for sure, it won't pass emissions inspection.

Bob Wilson

 

Is there an easy way to differentiate P1437 coming from the accelerator pedal or from a solenoid? What is more likely to happen?

 

Both my Prius's passed readiness with the Evap monitor not ready. MA may be different. You cannot, however, have a code set in the PCM and expect anything but an automatic fail. Even if the cel is not illuminated.

Toyota Prius P1437 - Toyota Prius 2003 Repair - Toyota Service Blog

Readiness monitors won't cause anything to blink on the dash.

 

More on P1437:
I have had this code "Pending" for a few months and a few hundred miles on a 2003 Prius. Clear it; it comes back "Pending" but does not set the CEL/MIL (Check Engine Light/Malfunction Indicator Light). I recall that when the HCAC valve (that big monster on the exhaust pipe, just after the catalytic converter) is stuck (won't move at all), it sets the P1436 code. I recently had to deal with a persistent (would always immediately set the CEL) P1430 on a 2001 Prius which resulted from a really-hard-to-see broken ground wire directly at the VCV sensor (the Vacuum Check Valve sensor, just above the dipstick).
I have inspected and lubed the HCAC valve on this 2003 Prius, so I know it moves freely and does not bind. All the vacuum hoses appear to be intact, but they ARE 14 years old. So I am now wondering if the wiring harness from the VCV to the Engine ECU has a damaged or corroded wire, possibly right at the sensor. The harness is vulnerable to severe bending when the dipstick is taken in and out. On my to-do list is to check all the voltages on the VCV sensor, and see if any are awry. That the code is "Pending" says to me that the car thinks the vacuum is operating, but the measured value is not right.
Problem: If the sensor output voltage (on the purple wire) is not correct, that does not allow me to distinguish between (a) poor vacuum supply (b) problem with the wiring harness, or (c) (lowest probability) a problem with the sensor. This is the problem with "remote" or "automated" diagnostics; it can only point approximately to where the issue is, when ALL possible causes are laid out.
I will admit to a certain bias towards suspecting the wiring harness because I DID just have that problem; wiring harness issues are usually a very low probability. Missing in the Toyota diagnostics is any direct measurement value of the expected vacuum pressure at the sensor, which I would expect to be the next immediate diagnostic step (split vacuum problem from electrical problem).
If other folks wrestling with this fault code have experiences with the fault they actually found (vacuum hose, wiring harness, HCAC valve operation, or vacuum generation, or other) it would be helpful to hear your stories.

 

Yeah if you have readiness monitors that aren't cleared, the last thing you want to do is clear the OBD2. Essentially, doing that puts the readiness monitors back to 'not ready.' Here in AZ, the evap readiness monitor can not be ready and it will still clear emissions. So if that particular monitor isn't ready, take it to emissions and have it tested. Betting it will pass.

 

This vehicle has two faults, which are independent.

P1437 relates to the vacuum system used to activate the HCAC control valve, located on the exhaust pipe just past the catalytic converter. This one could be a damaged wire, dried out vacuum hose, or a sticky HCAC valve. I'm wrestling with one of these right now on a 2003 Prius.

The blinking "EV" indicates that the Evaporative Control Monitor for the pollution testing has not completed its test cycle. This test takes several drive cycles to complete, and can be frustrated by an ill-fitting gas cap or corrosion at the fuel fill neck, which prevents the gas cap from making a good seal. So give the gas cap and fuel fill port a good looking over.