I am not sure if 91 190e has engine fault code scanner built in the
ECU. I think you need a special diagnostic tool, you really need to
post this qestion, I am sure there are experts in the field who
can help you. The three relays you are asking are, fuel pump,
AT kickdown and overvoltage protection relays. The OVP relay
is the one with 10A fuse. Meantime when you will be waiting
for answer to your question on engine fault codes, you can try
qucik couple of tests. One, you need to test OVP relay, second
test engine idle stabilization.
1. Disconnect battery,
2. remove ECU and disconnect plug.
3. Reconnect battery
4.Switch -on ignition, engine off, Test voltage from control unit
plug to termnal 1 to ground.
If there is a battery voltage present, end of test. OVP relay is OK
If there is no battery voltage you need to stop here. Send me a
private e-mail how can I fax you a copy of the rest of the procedure.
Engine Idle Stabilization test.
1. Ignitin on, engine off.
2. Gear shifter on P and N
3.Check voltage between ECU plug terminal 16 and battery.
If there is battery voltage present, OK. End of test. If not,
check Safety Neutral Switch, or repair broken wire between
ECU and SNS. This is only a partial procedure. If you a find
problem with idle stabilization let me konw.
Last edited by kjsabat; 03-10-2003 at 10:58 PM.