I have a 2003 2500 4X4 suburban with the 6.0. about 6 months ago I backed into my driveway and washed the exterior, I NEVER opened the hood and when I started her up the check engine light came on and the "reduced engine power" came on. I let her sit for an hour and she started right up with no issues, about 3 days later I hit a bump in the road and it happened again. I had the light checked and it said faulty tps. I replaced it and it still came on, I replaced the battery next then light stayed off for a day then came back on now with the brake light and abs light but only when I hit bumps in the road. to date I've replaced the tps, rear engine ground wire, throttle body, tac, battery, fuel pump, accelerator pedal and sensor, fuel filter, ive cleaned the grounds on the frame under the driver door and on the lf radiator pillar. And still when the motor warms up the check engine light comes on as well as the "reduced engine power" light. Now my horn only works when I set my alarm and not off the steering wheel. I'm at a complete loss and have friends stumped as to what is the cause. What else am I missing causing this issue? ANY input will be GREATLY appreciated and MERRY CHRISTMAS EVERYONE

 

can't help much without codes...is that the only code? and its the one set every time?

 

I am having the same issues and there's only one code that comes up p1518. I have changed the tps and throttle control module checked every fuse checked and wires for any frey or burnt wires