Hey guys,

I've had my 99 FRC for a couple of years now, and for the past year I've been battling two issues, primarily the "reduced engine power" message. I'm gonna lay everything out below, and if anyone has suggestions for what I could try next I would greatly appreciate it.

I bought the car about two years ago, and it was bone stock except for an aftermarket cold air intake. The car didn't have any issues at all. About a year ago I installed an SLP exhaust system from the stock h-pipe back with no mufflers. 6ish months later when slowing down for a red light or stop sign, the idle would drop down to about 400 and the car would almost die. After coming to a complete stop the idle would return to normal. This happened a few times and then the reduced power message occurred for the first time.

Fast forward to present day, just about every time I drive the car it goes into reduced power mode. Sometimes it will happen while going down the road and then go away after a few minutes, other times it will happen as soon as I start the car and won't go away. Turning the car off and back on three times does nothing.

The last time it happened, I hooked up a code reader to the car and got the following codes: U1301, C1245, C1255, U1016.

I've been told to purchase an HP Tuners kit and go to editor>engine diagnostic>predicted airflow, and change both tables to 4.10. Is this my next best option?

On a side note, around the same time that the reduced power started happening, the driver's window stopped working. The only way I could get it to work was to hit the door panel with my hand or close the door hard. I don't think it's the window motor because when it happens, the lights on the door's switch panel go out and it won't let me roll down the passenger window from the driver's side. Slam the driver's door and the lights come back on and I can roll both windows down again. I'm not sure if this is related to the reduced power mode issue, but I went ahead and removed the driver's door panel, cleaned all the connections, and replaced the window switch panel to be safe. No luck whatsoever though as the window continues to do the same thing.

If anyone has any tips for either of these issues, please let me know!

 

BOTTLEFED97

Call me and lets discuss your issues... I have some ideas. I believe you have MORE THAN ONE ISSUE at the current moment. We can easily resolve some of them;

YOU DO NOT need a code scanned to read your DTCs. You can easily sit behind the wheel and read ALL of your cars DTCs using the built in DTC reading routine. Using the built in DTC reading feature will show you ALL of the cars DTCs . A generac scanner will normally only show you PCM and maybe some chassis DTCs.

PM sent!

Bill

 

Bill thank you SO MUCH for the advice over the phone. I'll try it out tonight and will let you know how it goes.

For anyone else that might be having the same issue - there is a rubber accordion running from the body to the door that has two plugs inside of it. Simply squeeze the accordion and pull it out, then look for the plug with 6 pins. Bill's issue was that the female pins were not making good contact with the male pins, and when this would happen multiple signals would be sent to/from the DCM causing the window to not function and the reduced power message to appear.

 

Keith DeFazio from New Level Auto across the Raritan Bay from me in Staten Island...not the best video quality from him on this one but was doing it live...this was cranking no start. Those U codes will kill ya !!

 

YES,,, If any of the serial data wires are shorted, corroded to ground, wet or damaged, it will cause serial data buss issues. Most of the time, the door control module SIX PIN power plug inside the A Pillar has loose damaged female pins and that causes the door control module and or the seat module to turn ON & OFF, ON & OFF repeatedly which causes a corrupted serial data buss.

In that vid, the seat control module main harness connector was WETTED and the power pin was shorted to the serial data pin. Could have also happened to the drivers seat connector also.

Either way, the serial data buss got corrupted. YES, pop off the FOUR WIRE STAR CONNECTOR and you isolate the LDCM, RDCM and SCM from the rest of the car modules.

Bill

 

Well it's been five days now and no reduced power message! I'm thrilled and have been driving the car everywhere. Bill I can't thank you enough for your advice, you really saved me a lot of time and stress.

I did get a "charge system fault" message one time but I think it's because of disconnecting the battery.