ECU Replacement

inlineframe · Post by **inlineframe** » 03 Jun 2012, 12:26

My grandfather just purchased a really cheap 1999 Volvo s70 base, but it's really horrible. He loves to fix these cars up as a hobby but he's been having issues lately trying to diagnose the issue.

The vehicle was at a mechanics shop sitting for about half a year. The owner had the motor replaced with a new one, new struts, brakes, and tires. It took awhile to cold start it but it started up well. After a few minutes the vehicle would suddenly die. We've noticed that the mileage would disappear sometimes which in our minds it could be the ECU.

Would a 1998 s70 ECU work in the vehicle? I've heard that the 1999 s70's ECU are tied with the vehicle and cant be replaced.. Im a electronic engineer and looking into the components they have that weather proof junk that I really hate to remove, plus trying to extract the data from the chip will take more time than getting a replacement.

Lastly 2 codes came up; P0600 which appears to be either harness or ECU/ETM, which I think its the ECU.. Also, I dont remember the code but it said Lighting..Not sure what that meant..

Post by **vjaneczko** » 06 Jun 2012, 15:35

With the new motor (it's not really brand new, is it? If so, where'd he get it? I may need one

), were the vacuum hoses, MAF, spark plug wires, etc. also replaced? Another thought is how old the battery is and if the alternator is doing a good job.

Might be good to give it a Stage Zero review:
https://www.matthewsvolvosite.com/what-is-stage-0.html

Post by **jimmy57** » 06 Jun 2012, 18:22

99 is the first year where the ECM is mated to the car. The instrument cluster on that car is the master module with CDM (instrument cluster), ETM, TCM, ECM, and ABS CM being the CAN network modules.

Post by **BEJinFbk** » 07 Jun 2012, 18:26

+1 on confirming good system voltage. Mileage should always be displayed.
If it's going away, I'd suspect that you're dropping below operating threshold.

If this car has been out of service for a while and the engine was swapped,
there could be any number of things going on. You may want to start with
an electrical and charging system stage 0. Inspect all major connections,
check the alternator output and test for voltage drop on all primary cabling.

This MY has a history of aging problems with the B+ lead that feeds the
main fuse box. That fits the odo drop out pretty well - Don't miss that one.

Post by **abscate** » 02 Dec 2021, 06:37

jimmy57 wrote: ↑06 Jun 2012, 18:22 99 is the first year where the ECM is mated to the car. The instrument cluster on that car is the master module with CDM (instrument cluster), ETM, TCM, ECM, and ABS CM being the CAN network modules.

Found this info today while searching fir something else , good to know

I ******think ******* only the CDM AND ECM are coded to VIN STARTING IN 1999

Post by **scot850** » 02 Dec 2021, 10:40

+1 on this in terms of Vin#.

Neil.