124 / 202 idle fault
 

Hi all,

I have a 202 C180 with Siemens PMS. This will not idle due to no idle command from ECU. Also the stepper supply is 3.1volts. This had a rotten loom which I have repaired. It has the following codes, which will not clear.

003 - CTS Open
004 - CTS implausable
006 - IAT Short
013 - Idle in limp
022 - O2 Sensor High
023 - O2 Sensor cold open
027 - Inj 1/4 short
031 - Inj 1/4 open

I have recheked the wiring. The injectors, CTS, ATS and O2 sensors all check out ok too. The throttle pots check out good as well. I suspect an ECU fault but would welcome some input from someone who has seen this before. This old car is hardly worth the price of a new control unit.

I also have a 124 body here with the same symptoms and codes. Since I have two of them, I guess this must be common, though I have not seen it before. This has had a throttle body fitted already.

Any input welcome

Thanks

Alan

Hi all,

The info I had on the 5v supply to the stepper came from WIS. On further investigation it seems that this was meant to be a figure as measured with a dvom. I guess a digital signal might just show as this on a dvom. It should be a 12v signal. Mine is stuck at 3.1v output from ECU so it has to be a faulty ECU.

Another interesting thing, the list of codes I posted was read with a snapon scanner. there is a fault with the snapon software, it always shows these codes on this system. Thanks snappy!

Alan