Shoebox has the pinout diagram for connector C230: (click on tab at bottom of page, scroll down to 1996-1997):

http://shbox.com/1/harness_connector_faces.htm

You need to look for a 10-pin metri-pack connector, color = blue, with the wire colors shown in Shoebox's diagram.

The factory service manual shows the wiring schematic in volume 2 of 2, part 2 of 2, page 8A-81-3.

C230 is shown on page 8A-81-9, ,with wire colors shown on page 8A-202-7

The three connectors and wiring harness in that area are shown on page 8A-201-20

Plan view of wire harness routing is shown on page 8A-203-0, with location description on page 8A-203-2

Its all in the manual. Yes, its dogwork to find it, but that's really the only way to find accurate info.

 

I always forget about the manual, sorry about that!
Thanks alot for your help! Found the wire and connected another one. Next week going to get a socket and bulb and connect the whole thing.
Its not that easy to see the colors (at least for me...) I would have said that this looks more like somehow gray than brown, but o well. At least I'm one step in the right direction.

 

saved me 3 freeze frame from the P0400 (EGR) Anybody can see in these numbers anything wrong? On the last one I reinstalled the CAI and cleaned the MAF with spray for electronics (could this be the change in the fueltrim with the minus values?)
In the meantime the EGR-valve has been changed along with the solenoid. now it is possible to manipulate the valve via computer-device. But this is as far as we got the last time...
freeze frame 1:
Load-% 9.0
ETC 81°C
short fueltrim1: 1.6%
longfueltrim1: 13.3%
short fueltrim1: 1.6%
longfueltrim1: 10.9%
MAP: 50kPa
RPM: 1424
VSS: 76kmh
MAF: 23.7 g/s
TP: 11.8%
freeze frame 2:
Load-% 10.6
ETC 79°C
short fueltrim1: 2.3%
longfueltrim1: 12.5%
short fueltrim1: 1.6%
longfueltrim1: 10.2%
MAP: 54kPa
RPM: 1468
VSS: 61kmh
MAF: 27.04 g/s
TP: 14.1%
freeze frame 3:
Load-% 9.8
ETC 77°C
short fueltrim1: -1.6%
longfueltrim1: 12.5%
short fueltrim1: -3.1%
longfueltrim1: 10.9%
MAP: 48kPa
RPM: 1474
VSS: 79kmh
MAF: 25.04 g/s
TP: 11.0%

 

Short term fuel trims are toggled back and forth rapidly by the PCM, between slightly rich (+), and slightly lean (-). It does this to help the catalytic converter do its job. Hence, whether the freeze frame catches them in either state is not significant. More concerning is the long terms being above 10%, but that should not affect the EGR diagnostic.

Read the description of P0400 I posted way back in the beginning. The PCM cycles the EGR valve and looks for a specific change in the MAP reading. Your freeze frames would indicate the PCM is running the “Cruise Mode Test”, where the EGR has to be operating at a duty cycle above 94%, engine RPM is steady, throttle position is steady, vehicle speed is steady. At that point the PCM closes the EGR valve, and looks for a specific change in MAP. But the factory service manual (FSM) does not state what the magnitude of the MAP change is.

I don’t see any way to evaluate how a single frame of data can show anything other than that SOME of the conditions allowing the diagnostic to be run were in the correct ranges. The FSM indicates a need to have the “Failure Records”, “Fail Counter”, and “Pass Counter” data in addition to the Freeze Frame data.

Read the possible causes I mentioned in the earlier post. The P0400 description in the FSM tells how to check several of these. This whole system is so sensitive that having the two lines (intake manifold to solenoid, solenoid to EGR valve) on the EGR vacuum solenoid switched can cause the code. Starts on page 6E-657.

 

Ok, then I missunderstood a post I read a while back about useful information in frezze frame.


Now this is interesting. So replacing the old lines with new ones would be critical too when the length is not 100% accurate?

interesting read about the fuel trims:
https://www.autoserviceprofessional....t-work-for-you

 

Length of the vacuum lines (within reason) is not important, and the layout of the components dictates the logical length. Switching the lines to the incorrect connections affects the flow through the orifice inside the solenoid, according to the FSM. I would never have thought of that. A leaking vacuum line would prevent the system from operating correctly.

 

ok, sloooowly progressing...
tested vaccum at the lines to the EGR and the valve itself. One line from the solenoid to the valve and the 1-year old valve were leaking...
Replaced the line and ordered another valve.
Hopefully next week we can make another step forward when the parcel arrives!

 

today we found three vacuum leaks. one was huge. replaced those lines and the values for maf and long term fuel are back to normal.
maf today was 4.8-5.0 and the short term fuel were almost climbing to 20 when coming to a stoplight. Car felt like its dying and idle was below normal.
Afterwards felt like „new“ again. wondering if this cured also the egr problem since the new valve didnt hold the vacuum stable. hopefully stable enough (should be 20 seconds going by the manual) we will see tomorrow…

 

Good news. Where were the vacuum leaks you discovered?

 

the line from CCV to throttle body was a bit brittle, but there isn't a valve in between anyway
A small leak from the line between EGR solenoid and valve
the elbow at the PCV valve looked good from the outside but once the mechanic slightly teared it out it almost fell apart, had a huge hole on the inner side of the corner. Also the whole line was brittle to the throttle body.

There was another mechanic present at this time. He checked the "old" EGR-valve with his mouth... and yelled "hey, this still works fine"

So, the first two drives without a code. keeping fingers crossed that also this evening when I drive home from work it stays the same...

 

it looks like the problems are solved! drove 2 times two roads where the egr usually set the code. fuel trims also by +/- 0
maf by 7.5g/s
filled it up yesterday to see also if the mpg goes up again

 

Problems were not solved. Depending on the engine temperatur the code was set or not. At least, after install of the original t-stat, the code went off on a longer trip.
Now I have the PCM of an '96 installed, modified by Solomon for EGR-delete, works flawless...