new member ,upgrade obd1 to obd2

Hello everybody
I'm new to and new to XJ 4.l manual trans model 1995.238000km.
no modification at all. no playing in the steering at all. I was driving it with 160km per hour with one hand in my first trip back home with the a/c running and no over heating !! the air temperature was 48 c.

The only thing does not work is the check engine light !!! I'm not sure what is wrong with it?



I live in Egypt and the nearest repair shop for the
cherokee repair is 600km far from me !!

Would it be possible to upgrade the same engine from obd1 to obd2 without swap to another engine ?

So I can diagnose trouble better with scanner.I failed to get obd1 scanner
in my country.

I appreciate any input

abusamra

What year is your XJ? I didn't see that anywhere...

RENIX, OBD-I, and OBD-II all refer not to the engine itself, but to the electronic controls of the engine. So, it's possible to swap back and forth without having to swap the entire engine.

1987-1990 w/gasoline engine - considered RENIX. This is a pre-OBD control system, and these are the only years of the 242ci six that have an EGR valve (deleted for 1991-2001) and a knock sensor (deleted for 1991-2001.) The control system works very well; and, although the typical "code reader" won't work with it, the system can be mostly troubleshot with a decent DMM (Digital Multimeter.) It does not "store" or "throw" codes.

1991-1995 - OBD-I. Requires a Chrysler-specific OBD-I reader (each manufacturer had their own standard for OBD-I, or used someone else's.) Knock sensor and EGR valve deleted, significant changes to the cylinder head, intake manifold, and throttle body, and some sensors are different.

1996-2001 - OBD-II. OBD-II was standardised by SAE, which is why OBD-II readers are easier to find than the OBD-I reader you need. Similar to OBD-I, shares many parts (although there were some changes, I believe the sensors read in the same manner as OBD-I.)

Conversion from OBD-I to OBD-II requires getting an engine controller and wiring harness, and crawling into your engine bay and replacing everything. I do not believe that the wiring harnesses are the same between OBD-I and OBD-II, but having the manual transmission (if you're OBD-I, it's the Aisin AX-15, which is a decent gearbox,) simplifies things for you. Make sure you get an OBD-II engine controller from a vehicle likewise equipped with a manual transmission, or the controller will be looking for inputs from the transmission that you won't be generating (the AW4 four-speed automatic is electronically controlled.)

The reason I bring the RENIX system up is simple - being pre-OBD, the CEL (Check Engine Lamp) is not used. There is a window for it - the instrument cluster was also used with the OBD-I GM 2.8L V6 1984-1986 - but it goes without a lamp behind it for RENIX.

If you're converting from RENIX to OBD-II, you're in for more work - swapping out the cylinder head and manifolds (referred to as the "top end") all the way to the catalytic converter flange will make things easier for you at the intake and throttle body sensors. The RENIX TPS works in the reverse direction of the OBD TPS (it's a variable resistance used as a voltage divider,) so it has to be adapted somehow - I leave that as an exercise for the creative student.

However, you'll find most of the items that want repairing on the XJ to be relatively simple to perform with common hand tools (it's probably one of the easiest vehicles I've worked on made in the last thirty years!) so you're not likely to need that repair shop 600 klicks away!

Uh? Jon? End of second line. 1995, 238k on the odometer.

Like Jon says, that's a fairly involved electrical job. You've got an AX15 manual transmission, so you don't need to worry about the TCU.

ChiXJeff said:

Uh? Jon? End of second line. 1995, 238k on the odometer.

Like Jon says, that's a fairly involved electrical job. You've got an AX15 manual transmission, so you don't need to worry about the TCU.

Click to expand...

Duh-uh. Yeah, I just saw it. He separated it with the decimal, which probably threw me off a tiny bit...

Does keying the ignition work on overseas model cherokee OBD1 systems? Might be an easier way out

Thanks for the reply

The car registered as 1996 model in my country.
But after deep searching the Internet I found out that it's 1995 model !!
I've got the history of the car from one of the web sites by entering VIN number.
And that what I've got:
JEEP VIN Decoder 1.64

VIN : DA2FJ33V8SE037467
Symbol
D
A
2
F
J
3
3
V
8
S
E
0
3
7
4
6
7
Position
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17




Control (check) digit calculation





I didn't understand why it didn't pass the control digit check ?

I found that also from the Data Link Connector,It's an SCI connector.

Do you think would it be possible to swap a control module from later years
So I can diagnose it better.Plus I failed to get an obd1 scanner in my country.
But with obd 2, a simple cheap scanner would work

I live 600 km far from the nearest cherokee repair shop !!

Cheers
abusamra

is the problem that you have a check engine light on? I re-read your original post and it seems more like that is what you were meaning. If all you need is to find out what is wrong and what the light means there is an easy way.

Turn ignition switch on and off 5 times leaving it on the 5th time (do not start the motor)
watch the check engine light, it will start blinking.
count the flashes. It will blink a series, pause then blink another series.
the codes are two digit and it will flash as described above, then move on to the next code after a longer pause.

ex:
55, 23, 17: ....._..... __ .._... __ ._...... (the periods are the light flashing, lines are pauses)

hopefully this helps you get moving towards where you need to be. I would not want to try to swap the entire thing over to OBD2. It will not be as easy as swapping in the new computer and being done. You will need to change over the entire harness and change some of the sensors as well to make it work.

ChiXJeff said:

Uh? Jon? End of second line. 1995, 238k on the odometer.

Click to expand...

238,000 kilometers is only 148,000 miles. :dunno: