ECU Problem
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Joined: Oct 2013
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C280
ECU Problem
The car is a 1995, C280. The car was running fine and was a solid daily driver. I was seeing oil sludge in the coolant and it was beginning to run hot (110C), so decided to replace the head gasket.
Here's the status of the car before the work:
- New wiring harness from a previous owner
- Throttle body also rewired
- I have a STAR and was able to communicate to the ECU
- No Codes
- Starts easy and runs great
- Newish OVP
As for the head gasket - standard stuff
- New gaskets all around
- Head not rebuilt but was resurfaced (VERY minor)
- Basic parts replaced - hoses, thermostat, spark plugs, head bolts
- Tested/Cleaned injectors
After the repair, the car started fine when cold but and performs normally with the standard 1200 RMP then slowly settles to 700 RPM. But after it warms up, it begins to stumbled and hard start. I was able to communicate with the ECU for many days while troubleshooting the engine. Then the ECU stopped communicating with the STAR. And there was no voltage at the VVT solenoid. The STAR error message was "Turn ignition on." In short, it feels like the ECU is not attempting to talk to the engine either.
I sent the ECU off to a repair/reman service. They reported the CPU was fried, was not repairable, and sent me a cloned remain unit - programmed as a plug-and-play replacement. This "new" ECU also did not communicate and the company sent me another replacement...also same result. Assuming they are providing a good product and it's programmed correctly I have to believe I have an issue with the car.
Sorry for all the background... I agreed with the ECU repair companies assessment of my first ECU because I took a risk and used a battery charger to jump start the car (I know, I'm paying for that decision now). Based on the way the car was running and their report, I figured my actions were the root cause that fried the original ECU. But now that I've had two attempts at a cloned remain I've hit a wall regarding next steps. So I'm asking for some experts to help with the troubleshooting process.
Much thanks for your help!!
Here's the status of the car before the work:
- New wiring harness from a previous owner
- Throttle body also rewired
- I have a STAR and was able to communicate to the ECU
- No Codes
- Starts easy and runs great
- Newish OVP
As for the head gasket - standard stuff
- New gaskets all around
- Head not rebuilt but was resurfaced (VERY minor)
- Basic parts replaced - hoses, thermostat, spark plugs, head bolts
- Tested/Cleaned injectors
After the repair, the car started fine when cold but and performs normally with the standard 1200 RMP then slowly settles to 700 RPM. But after it warms up, it begins to stumbled and hard start. I was able to communicate with the ECU for many days while troubleshooting the engine. Then the ECU stopped communicating with the STAR. And there was no voltage at the VVT solenoid. The STAR error message was "Turn ignition on." In short, it feels like the ECU is not attempting to talk to the engine either.
I sent the ECU off to a repair/reman service. They reported the CPU was fried, was not repairable, and sent me a cloned remain unit - programmed as a plug-and-play replacement. This "new" ECU also did not communicate and the company sent me another replacement...also same result. Assuming they are providing a good product and it's programmed correctly I have to believe I have an issue with the car.
Sorry for all the background... I agreed with the ECU repair companies assessment of my first ECU because I took a risk and used a battery charger to jump start the car (I know, I'm paying for that decision now). Based on the way the car was running and their report, I figured my actions were the root cause that fried the original ECU. But now that I've had two attempts at a cloned remain I've hit a wall regarding next steps. So I'm asking for some experts to help with the troubleshooting process.
Much thanks for your help!!
