Ok, Just built the code reader and got the codes.
Pin 8 Gave:
4 Hot film mass air flow sensor
13 O2S (Lambda) control system operating at rich or lean limit
21 Ignition output 3 or ignition coil for cylinder 1 and 6
23 Ignition output 2 or ignition coil for cylinder 3 and 4 (Engine 111, cylinder 2 and 3)
28 VSS - open circuit
41 CAN communication from engine control module faulty
42 CAN communication from ASR, EA/CC/ISC module or diagnostic module (OBD II) faulty
43 Starter signal (circuit 50) not present
and Pin 14 Gave:
5 Stop lamp switch (S9/1)
9 Left rear axle vehicle speed sensor from ABS/ASR control module or in 124 chassis
11 Closed throttle recognition signal to engine control module (HFM-SFI or Left LH-SFI)
Fuel safety shut-off to engine control module (HFM-SFI or left or right LH-SFI)
Obviously those are codes stored from who knows how long ago. Some are from running the engine with the crossover pipe un-attached and from the bad fuse on the OVP Relay. I should clear them and take it for a drive and then see.
But there. Now we have something. Thanks for the tip on the OVP Jeff.
By the way here's my tester (made from junk laying around). I used a cheap guitar pedal and some old test leads from a harbor freight multimeter for the banana plugs. I put a 1.5k resistor from the hot lead to the LED to keep it from burning out under 12 Volts. Works great! The pedal has the perfect momentary switch. I have a pile of these pedals (used to mod them and resell). This is equally useful as when it was a guitar pedal. Actually more useful! Saves a trip to the dealer. Thanks Arthur Dalton and others who posted the info on the test setup.
