P2121 and P2122 OBD codes, "Reduced Engine Performance" message, engine will not rev above 1,000 RPM in Drive on 2004 S6

[firstv70volvo]

Have you checked the fuses in the engine compartment? I read one of the fixes for these codes was replacing a blown 10A fuse (slot 11?) in the engine compartment, It's the fuse for the accelerator pedal sensor, cooling fan for electronics box engine compartment and AC compressor solenoid switch. I don't have a wiring diagram for the S60 so not sure about the slot number of the fuse, it's slot 8 for my 2001 V70 but someone said it's slot 11 for the S60, just not sure but it's not difficult to check all the fuses in the engine compartment. Does your AC compressor work?

I checked my fuses and discovered that slot #8 fuse is the one that controls the throttle pedal sensor and the AC clutch. AND it was blown! So I immediately replaced it and started the car but nothing had changed.

So, I took a look at that fuse again and discovered that the replacement I had just installed 5 minutes earlier was also blown. I found another 10A replacement and repeated the process. Yep, that fuse also blew! Having now exhausted my supply of 10A fuses, I ordered some more from Amazon (they're out for delivery right now) and did some additional Google-ing. Once it is lighter out, I'm going to disconnect the wiring connector to the A/C compressor clutch and try replacing the fuse yet again to see if it continues to blow. Wish me luck!

For the AC compressor you can pull the AC relay FMI1 in the same engine compartment fuse box and see if the fuse survives. If it's not the AC compressor then it may be the cooling fan for the electrics box in the engine compartment. My car doesn't have this fan that I know of but I assume it's for the ECM/TCM. I think you're close to solving the problem.

[ericbeatty43]

Thanks for the tip about the A/C relay. I'll give that a go to disable the A/C so I don't have to skin up my knuckles trying to wriggle my hand down to the wire connector on the compressor.

[ericbeatty43]

UPDATE! Problem solved!

I removed the FMI1 relay for the A/C, replaced the 10A fuse in the #8 position of the underhood fuse box and everything was normal again. Now, my next task is to track down the short in the A/C compressor/clutch wiring. Luckily, here in the Pacific NW, I won't be needing A/C until some time in late July or August and then only for a few weeks at most.

Nevertheless, I'm not going to wait that long on it. Thank you again to everyone who contributed to my finding the (interim) solution!

[firstv70volvo]

UPDATE! Problem solved!

I removed the FMI1 relay for the A/C, replaced the 10A fuse in the #8 position of the underhood fuse box and everything was normal again. Now, my next task is to track down the short in the A/C compressor/clutch wiring. Luckily, here in the Pacific NW, I won't be needing A/C until some time in late July or August and then only for a few weeks at most.

Nevertheless, I'm not going to wait that long on it. Thank you again to everyone who contributed to my finding the (interim) solution!

If you have a meter you can measure resistance to ground using the pin 87 socket with the AC relay removed. I'll bet it's the clutch coil in the AC compressor that's shorted to ground, you can measure the resistance with and without the AC compressor wire connected to determine if it's the coil. Could be a short in the wiring too but less likely, measure resistance to ground for both 87 and 30 sockets to check the wiring, AC compressor wire disconnected .