P0604 (2) Chevrolet Uplander I

The ECM is unable to correctly write and read to and from random access memory (RAM) during the following conditions

1. Key up initialization for one count. Each count is a read and write sample. Each sample is 100 milliseconds. This portion runs once per ignition cycle.
2. Counter increments by 10 for each sample that does not correctly read and write to the RAM and decrements by one for each correct sample. No more than 20 counts which do not read and or write correctly. Each read and write sample is 100 milliseconds. This portion runs continuously.
3. Counter increments by 10 for each sample that does not correctly read and write to the Desired Throttle Position RAM and decrements by one for each correct sample. No more than 20 counts which do not read and or write correctly. Each read and write sample is 12.5 milliseconds. This portion runs continuously.