qblue90
Active member
- Joined
- Jun 2, 2008
- Messages
- 43
- Location
- S.E. Michigan
- Corvette
- 1990 Quasar Blue 6 spd,Z51,FX3,J55,GT7
Hi Guys!
My 1990 had a communications issue between the ECM and the CCM. After going through all the steps in the FSM ie. verifying wiring and grounds, we decided to replace the ECM. The replacement ECM fixed the communications issue, but immediately caused another to pop up with the fuel gauge. This was not a problem with the original ECM and started as soon as the new ECM was installed. By new ECM I mean new to me.. remanufactured.
The problem is this: once the fuel gets just below a half tank. Say 5 bars left showing and after I have driven about 5 miles, the bars will disappear one by one within a few minutes until the fuel gauge reads empty. Even though there is still 5 bars worth of fuel in the tank. If I shut the vehicle off and allow it to sit for an undetermined amount of time, the 5 bars will show back up on the gauge at start up. But they will disappear down to empty again when I drive for any short length. This happens with any amount of fuel below 1/2 tank and seems to be getting worse. It has even gone in the opposite direction - indicating a full tank- a couple times when it only had a 1/2 tank.
Has anyone else experienced this?
Does the ECM control the fuel gauge?
My thoughts are that the remanufactured ECM had this issue and it was not discovered and I need another ECM.
I would like to avoid having to check the sending unit if I could. Especially since my logic tells me that this was not happening with the original ECM and started immediately with the remanufactured ECM.
Any advise would be greatly appreciated.
My 1990 had a communications issue between the ECM and the CCM. After going through all the steps in the FSM ie. verifying wiring and grounds, we decided to replace the ECM. The replacement ECM fixed the communications issue, but immediately caused another to pop up with the fuel gauge. This was not a problem with the original ECM and started as soon as the new ECM was installed. By new ECM I mean new to me.. remanufactured.
The problem is this: once the fuel gets just below a half tank. Say 5 bars left showing and after I have driven about 5 miles, the bars will disappear one by one within a few minutes until the fuel gauge reads empty. Even though there is still 5 bars worth of fuel in the tank. If I shut the vehicle off and allow it to sit for an undetermined amount of time, the 5 bars will show back up on the gauge at start up. But they will disappear down to empty again when I drive for any short length. This happens with any amount of fuel below 1/2 tank and seems to be getting worse. It has even gone in the opposite direction - indicating a full tank- a couple times when it only had a 1/2 tank.
Has anyone else experienced this?
Does the ECM control the fuel gauge?
My thoughts are that the remanufactured ECM had this issue and it was not discovered and I need another ECM.
I would like to avoid having to check the sending unit if I could. Especially since my logic tells me that this was not happening with the original ECM and started immediately with the remanufactured ECM.
Any advise would be greatly appreciated.