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1995 Sl320 a plethora of DTC's.Mystery.......H.E. E.L.P.

I don't quite know what to think about this problem. Yesterday the MIL came on . The car seemed to drive allright and I did not notice any degradation in performance. I did a generic OBDII diagnostic with a laptop interface program/connector at the OBDII connector and there were no trouble codes stored but the MIL showed up as illuminated. I cleared the non existent trouble codes, the MIL went out and I was happy thinking I was home free. I started the engine several times and the light stayed off. This morning the MIL was back on again. This time I got out my Trisco scan tool and retrieved these MB trouble codes via the 38 pin connector

007 Intake air sensor open circuit 015 Throttle valve pot actual value too low 022 EFP actuator signal in limp home mode 025 02 Sensor signal before Catalytic Converter incorrect 029 O2 Sensor Heater before Cataluytic converter too small current 030 O2 Sensor Heater before Catalytic Converter current too large 033 O2 Sensor Heater after Catalytic Converter current too large 039 Inj Valve cyl 2 shorted to positive 045 Inj Valve cyl 5 shorted to positive 047 Inj Valve cyl 6 shorted to positive 054 Mixture too lean at upper part load, Vacuum leak inj pressure regulator/wear engine 061 Ignition sys output stage 3 cyl 1 misfire

I checked for codes at the OBDII connector with my lapttop/scantool interface and there were no DTC's to retrieve.but the MIL was on. The O2 sensor test showed that the system was functioning OK and in closed loop. Again I cleared the non existen DTC's and the MIL went off.

Does anyone have a clue regarding what seems to be going on here . Is the ECU on the way out ? I find it hard to believe that the car can have all these problems and still run all right.

The car now has 93k miles. The wire harness apears OK. probably has already been replaced. Anything else to look for?

Thanks Peter

Reply to
Peter W Peternouschek
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You are trying to read OBD II codes on a OBD I car!!!!! It does not work that way...... You need the old school MB HHT to read those faults.

Another thing that people don't realize is that generic scan tools for OBD II only read the P0xxx codes. MB's also have P1xxx and P2xxx codes that go deeper to explaining the fault. By law, the generic tools have to read the P0xxx faults, which they do.

Reply to
Karl

My 1995 SL320 is an OBDII car. The Electronics for this car are a mix of digital and analog. The generic OBDII interface adapter and program for my laptop computer that I use worked fine for me once before and displayed the correct PXXXX code when I had a problem with an O2 sensor sometime back. On this go around however no PXXXX codes came up at all.

The TRISCO scan tool that I used to get the codes from the 38 pin connector is MB specific and displayed all the codes shown in my initial post. It is my understanding the the Trisco scan tool is similar to the MB HHT.

II only read the P0xxx

the fault. By law, the

program/connector

Reply to
Peter W Peternouschek

The Trisco tool is the right tool for your car. Karl was just saying on the OBDII part. As for your problem... is it possible you got a main wiring harness problem? That is just too many DTC at one time.

ECU is always the last culprit... Computer on cars are super reliable that they are rarely at fault, except for the newest cars on the market... that's a different ballgame because there are too many computers.

Reply to
Tiger

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