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  #1  
Old 09-29-2012, 01:57 AM
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Can use multimeter on maf, lh module, ezl and eta?

1992 400e, wont start, sat for 4 years but thats another story.

I verified fuel to fuel rail & spark, new spark plugs and fuel filter installed. Fuel pump makes noise. Checked injectors for resistance (all .014 ohms). Injector wires are getting power.

From research the possible culprits are lh module, ezl, maf and throttle body. Can I check these parts with a multimeter as well? Also, am I on the right track with this diagnosis? Thanks..

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  #2  
Old 10-01-2012, 08:24 AM
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Possibly, OF course the fuel tank MUST be removed & completely cleaned before going any farther.

Then you need to inspect the 2 distributor caps!
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  #3  
Old 10-01-2012, 11:34 AM
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Agree

Quote:
Originally Posted by mbdoc View Post
Possibly, OF course the fuel tank MUST be removed & completely cleaned before going any farther.

Then you need to inspect the 2 distributor caps!
The fuel tank MUST be removed & completely cleaned before going any farther.





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  #4  
Old 10-01-2012, 08:05 PM
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I siphoned out the old fuel, is that enough or should i still remove fuel tank?

I built a homebrew dtc scanner and finally got it working today.
The following are the codes:
slot 6 - 11 flashes
slot 7 - 5
slot 8 - 6
slot 16 - 1
for slots 17 & 19 the led just stayed on, not even one blink.

Theres also the on board led test module, that gave me 17 flashes.

A member from e500 board let me use his palmscan dtc scanner, it showed data error, no ecu control or no data and no data for all the systems except the OP system.
OP systems codes:
1. Code 5 - module box temp beyond limit.
2. Code 6 - cooling air compressor electromagnetic clutch close tightly.
3. Code 10 - power supply pins 38, 15 & 34 contact not well. Bm module box connected. Wire fuse f2 open.

I deciphered the homebrew codes also:
pin 7, 5 = can databus: message from ea/cc/isc module faulty (n4/1); message from abs/asr module faulty (n30/1); message from lh-sfi module faulty (n3/1)
pin 8, 6 = a/c electromagnetic clutch jammed or poly-v-belt broken.

Any ideas? Bad harness? Bad LH or BM module?

Last edited by 92e400; 10-02-2012 at 12:14 AM. Reason: new information
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  #5  
Old 10-02-2012, 02:29 AM
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The homebrew tester says lh-sfi module shows faulty signal (pin 7, 5 flashes). The palm scanner gave data error for the di systems (ezl) and no car data for sfi system (lh module).

I remember reading that the lh module reacts to data from ezl. Could this mean that the ezl is the problem?

What do you guys think?
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  #6  
Old 10-03-2012, 12:06 PM
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So I found you . . . .

1) The fuel tank MUST be removed & completely cleaned before going any
farther. Both WH an MBDOC have stated that unequivocally.
2) The engine wiring harness MUST be replaced after cleaning the gas-tank.
3) Check the battery! A low battery will cause random DTCs to be set. If it's been sitting for 4 years, it may need replacement?
4) After those tasks are complete, you can read some stored DTCs and post them.

I would recommend that you reset all codes first and then read them after a few days.

If you don't attack this problem in the recommended manner, you may never solve it!
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  #7  
Old 10-03-2012, 06:37 PM
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Hey Jim,

You've found me.

I replaced the upper wiring harness. When you say engine harness, do you mean all of them or just the upper?

Theres a new battery in the car.

Will the dtc's reset without the car running? I havent been able to get it to fire up once.


Regarding the homebrew tester. I used the exact button switch as recommended by your manual and it worked on all the pins except 4, 17 & 19, pre harness change. After the harness change it lights up led immediately when i insert the wire into the pin.

If you guys say to clean gas tank, I will.

update edit:
Ran the palm scan reader today; ea/cs/isc system give code 96 - starter lock-out. Will this keep the car from starting?
The scanner communicates with op & ea/cs/isc systems but not with di, ezl and sfi.
Any ideas? Thanks.

Last edited by 92e400; 10-03-2012 at 08:52 PM.
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  #8  
Old 10-04-2012, 11:20 AM
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Comments below . . . good luck!

Quote:
Originally Posted by 92e400 View Post
I replaced the upper wiring harness. When you say engine harness, do you mean all of them or just the upper? <-- It's best to do both

Theres a new battery in the car. <-- That's good b/c it would need one after sitting for 4 years.

Will the dtc's reset without the car running? <-- no, as far as I know. Car needs to run. But it best to reset them after the car can runs b/c some DTCs may be phantom codes.

Regarding the homebrew tester. I used the exact button switch as recommended by your manual and it worked on all the pins except 4, 17 & 19, pre harness change. After the harness change it lights up led immediately when i insert the wire into the pin.

If you guys say to clean gas tank, I will. <-- it's mandatory!

update edit:
Ran the palm scan reader today; ea/cs/isc system give code 96 - starter lock-out. Will this keep the car from starting? <-- sure will if it's corroded and most are after 20 years!

The scanner communicates with op & ea/cs/isc systems but not with di, ezl and sfi. <-- hb code reader can not read digital codes. The Palm scanner should do that.
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  #9  
Old 10-05-2012, 09:13 PM
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1- The lower engine harness connects to the starter, alternator, and oil pressure/level senders. This won't prevent the engine from starting (assuming the starter engages and the motor turns over), nor should it trigger any DTC's.

2- DTC's will clear/reset without starting the engine, with the exception of some DM (Diagnostic Module) codes, which may require a re-start. The other modules only require cycling power on/off via the ignition switch; usually 10 seconds off after clearing codes will do it.

3- Digital code 096 (starter lockout) on the E-Gas module (which is analog code 6) should not prevent the engine from starting, if the starter is engaging. This code can cause an intermittent limp-home mode, but otherwise if the starter cranks, the engine should fire.

4- I have no idea what "OP" is but there is no "OP" module on the 124.034/.036 chassis. Sounds like the Palm scan is using an incorrect acronym for the Basic Module (BM, aka General Module) as the codes described are BM codes.

5- Please use this document when translating 124.034/.036 error codes. DO NOT trust any translation from the Palm Scan.

6- Before going crazy pulling the fuel tank, check fuel pressure at the Schrader valve on the fuel rail, near the front of the intake manifold. When you turn the key on, the fuel pumps should run for 2 seconds, and pressure should be 40-50 psi (approx). If you are getting fuel pressure at the rail, it's not likely you have a problem with either the pumps or tank strainer.

7- You said you replaced the upper engine harness, was it a newer harness, dated 2000 or later?

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  #10  
Old 10-05-2012, 09:34 PM
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I wouldn't go through the trouble of pulling the tank just yet, unless you like doing work that may not need to be done.

--> As GSXR said, check for fuel first then check the codes <--

Depending on how much gas is in the tank you MAY have to drain 80% of it, add 5 gallons of some known brand like Shell Premium, Chevron or the like, dump in some cleaner WITH TECHRON and run the engine. The change the fuel filter, put more gas and see how she goes. Only THEN consider dropping the tank. Again, why go through the troubling work if you don't have to? You can always do it later IF it needs it.
Do the simple, cheap things first, otherwise you're just throwing time and money in the wind and guessing what it may need.

Kind Regards,

Ron
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  #11  
Old 10-26-2012, 10:26 PM
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Update:

New fuel pumps, cleaned gas tank, new fuel exit hose, new fuel vent valve, she started without a hiccup.

Now theres a water leak in the passenger rear of engine. Any ideas? Thanks.
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  #12  
Old 10-27-2012, 04:36 PM
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Check for leaking Welch plugs. Dry everything and start the vehicle. It should start leaking immediately so feel along the plugs for a wet one. Do this with the vehicle cold though or you are in for a few nasty burns!!!

Check for a leaking hose first obviously. With age they tend to spring leaks on clamps.

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