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· Registered
27 Posts
Discussion Starter · #1 ·
Hi all,

I'm trying to chase down the cause for my readiness monitors not setting despite completing the drive cycle several times.

While doing this I figured it could have to do with a faulty O2 sensor as I also received (only once) a combustion too lean CEL. So I hooked up my OBD2 reader to check live data and...

There was almost nothing available.

A year ago when I looked at live data I saw maybe 16 measured values. Today, I am only seeing these values:


Rpm seems nominal, and DTC_CNT is zero, showing no codes. I indeed have no stored or pending codes according to the reader. I took this to a local O'Reilly and their reader confirmed that I was only streaming these 4 data points.

Any ideas on what this could indicate/cost to fix?

· Registered
27 Posts
Discussion Starter · #2 ·
I disconnected and reconnected the hybrid battery and got some information back on mode $08. 27 data points, including my O2 sensors, but still some stuff missing and some modules not being present.

Also still nothing on $01.

Checked the F1 ECU fuse, wasn't blown. Couldn't access the ACM or IMA fuses though. Will have to pull more apart to get at those.

I've heard that there should be 12v present between pins 16 and 4 on the OBD port, so I'll check that once my DMM is returned to me.

· Registered
27 Posts
Discussion Starter · #3 ·
Back for an update.

I have reconditioned the hybrid battery of this car and things are running great.

Unfortunately the readiness monitors are still not set for the car, and this problem with OBD2 modes persists. I do not know if it is actually a problem or not, but I can definitively say that in mode 1 ($01), the monitor statuses are:

Misfire monitor - N/A
Fuel system mon - N/A
Comp. Component - OK
Catalyst mon - N/A
Htd catalyst - N/A
Evap system mon - N/A
Sec air system - N/A
A/c refring mon - N/A
Oxygen sens mon - N/A
Oxygen sens htr - N/A
Egr system - N/A

Whereas in mode $08 (with 30 live data points):

Misfire Monitor, OK
Fuel system mon, OK
Comp. Component, OK
Catalyst Mon, OK
Htd catalyst, N/A
EVAP system mon, INC
Sec Air System, N/A
A/C refring mon, N/A
Oxygen sens mon, OK
Oxygen sens htr, OK
EGR system, OK

So I suppose now the question is, does the smog check use mode 1? Can it use mode 8?

Further, do the heated catalyst, secondary air system, and AC refrigeration monitors even exist on my car? If not, then in theory I should be good to go. However, this is the same state the car was in when it first failed smog, citing O2 monitor not ready. This makes me suspect the missing data in mode 1.

I very badly would like to get this car properly smog checked. I've put a lot of work into fixing it up and it's mechanically running great. I even get 30mpg. It would be terrible to be unable to use it because of some bits not setting in the computer.

· Registered
27 Posts
Discussion Starter · #5 ·
@vvKool what is the result of this test from the (non-hybrid) service manual?

View attachment 545151
That's been my reference for the monitors not being set. It does blink 5 times after a short period.

With a borrowed scan tool I've noticed that it throws up 10 monitors being N/A and 1 being OK before I select which diagnostic mode I want to use. It also agrees that in mode $01 there are 10 N/A monitors, and in $08, only the same 3 I wrote above being N/A.

Further, there is no mode $03 or $06, which I thought were fairly normal to see.

· Registered
27 Posts
Discussion Starter · #6 ·
Called around today to get some opinions...

"You might be the only person in the world right now with this problem"

Opinions are split on whether the ECU could be responsible.

I sort of envision an ECU failure as more catastrophic than this, so I can see why. At the same time, I don't know how data can just disappear in one mode and be available in another.

· Registered
27 Posts
Discussion Starter · #7 ·
I've done the DLC Circuit troubleshoot procedure outlined by my car's Chilton manual:

I don't have a known good ECU/ECM/PCM to test with, so I had to skip those parts. But everything involving continuity and voltage checked out.

Visually, the connections look clean and seem correct.

I'm out of (simple) ideas. The next thing I have in mind is CAN sniffing or pulling the ECU and giving it a visual inspection. Has anyone done either of those things before?
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