1994 E320 Code 6 Idle Problem
I'm having trouble with my 1994 E320. It has the check engine light on and is storing a code 6 (Idle control problem). I have cleared the light 4 times by disconnecting the battery and after about a day of driving the code sets itself again. At least it's consistent!
I checked the OVP and it was the old part number, so I replaced it. I have also replaced the coil connectors and plugs. These had no effect on the problem.
Here are the symptoms:
Before the check engine light sets itself, The idle is around 700 in drive w/o the A/C on and drops to 500 with the A/C on. It idles and runs smoothly.
After the check engine light comes on, the idle drops to about 400 and gets rougher. It's not really enough to keep the power steering going and I need to keep my foot on the gas a little to get it to idle when I first start it.
Please guide me towards the next round of diagnosis or the next obvious parts to test/replace.
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