Since I removed my burned out secondary air injection pump a few months ago I have had a CEL on permanently. I refused to pay the dealer price of $ 1000.00 for a new one and used they are around $ 450.00. Since I have installed a completely new exhaust system with headers and we do not have emissions testing in my country, there is no reason to fit a replacement pump.
Shardul was kind enough to send me the method of 'switching off' the secondary air injection pump and exhaust 02 sensors using a STAR, but my car refuses to co-operate. After spending the morning with my ex-AMG indy, he has made the following observations. Firstly he noticed that my windshield is not the original factory fitted one and said that this is the cause of many an AMG headache. Because the windshield is not fitted 100% correct, water is able to leak in at the bottom of the windshield near the wipers. The water then seeps in under the dash and nails the gateway unit. Once this gets wet it can cause the car to sporadically not start when parked at a certain inclination or after being washed. It will also prevent, as in my case, either the STAR or MB diagnostics tool to fully communicate with my ECU. We have tried both tools on my car and can only access certain parts of the ECU and sometimes none. Sometimes we just get 'communication error' or something to that effect. Yesterday we actually got to the part where we had the option on 'ein' or 'aus' to cancel the damn pump, but the ECU would not allow us to save either and shortly thereafter we got the dreaded 'communication error' message. I have heard a few times that the gateway unit causes problems and it is also a serious PITA to replace because it requires vehicle coding from the dealership. My indy has suggested that I remove the gateway unit, dry it out as best as I can, lightly sand off any rust on the connectors, seal it in a ziplock plastic bag and re-install it so we can have another go at accessing the ECU properly. I have complete trust in his advice and I will have a go at it before and fork out the money for a replacement part. My question is, has anyone else had leaking windscreen/gateway troubles and how did you remedy it without replacing it?

 

The CGW doesnot require any coding from the dealer. All you have to do is swap it out when the car is connected to DAS. The CGW doesnot store a lot of infomation it just acts as a communication bridge to the rest of the modules in the car.