Ok guys needing some help! I love driving this car but cannot get the full enjoyment due to problems with the car. When accelerating the gauges fluctuate then freeze, all warning lights come on,(battery, abs, low tire,- looks like when you initially turn on key) and the power steering shuts off, however the engine continues to run. When cold it happens at about 6000 rpm, as it warms it will occur at 3700 rpm and sometimes as low as 2500. I could originally lower rpms a minimal amount and everything would return to normal when shifting between 5th and sixth. I have looked for shorts without success. Alternator checks out good with maximum volts of 14.6. Battery is charged and checks out good at 12.7 volts. Crankshaft dampener replaced and had no effect on problem. All grounds appear good. It started out with just the gauges fluctuating and has gotten worse with all the other issues. I am leaning toward a bad ECU but hoping someone will have better grasp of what to do or where to look.

 

I have no clue for an issue like this to be honest, but i saw a previous thread on something somewhat similar? Hopefully that can help you or help eliminate some.

https://www.northamericanmotoring.co...e-haywire.html

 

Recently I had the TMPS and DCS light come and go. Every once in a while the gauges would go crazy like yours. Turns out it was the Tach. Someone else had the same problem as me and he replaced the tach that solved his problem. my car has been good for two week since replacing the tach. Hope this helps

 

That happened to my car when my alternator went. Given that the R53's are well over 10 years old, it is likely a lot of your moving parts are wearing out. Alternator, power steering pumps (if not replaced under warranty), belt pulleys, tensioners, water pump, etc. If you really like the car, then you will have to start spending money to replace parts. My exhaust header headshield fell off recently. It literally wore itself off. The holes where the bolts went through had worn bigger than the bolt.

When all the electricals fail but your car is still running, that means the alternator is not supplying current and you are running strictly on your battery until the battery dies. I got about 5 miles on the highway before the battery ran out also.

Since it sounds like your car still sort of runs, it might mean your alternator isn't totally dead yet but intermittently failing. You should get that diagnosed.

 

For a possible cheap fix, turn off your DSC (toggle in center switch panel) after startup and see if that makes a difference.

 

I am prepared for having to repair things, so far in the past few months Since owning the car only a short period of time I have replaced the alternator, clock spring, idler pulley, belt tensioner, harmonic balancer. Battery cables, and checked all grounds, replaced all breaks and rotors, and am about to replace ABS sensors as I do have a speed sensor code showing up on the scanner. Also have installed a 17% pulley. None of these have had any impact on the issues I am having. I had hoped the clock spring, grounds or alternator would have had an impact on the issues but so far nothing. Abs sensors will go on this weekend but not expecting that to help with the electrical issues but hopefully I am wrong.

if this doesn’t help I plan to change out Tach as suggested in another reply. If that doesn’t help I will save up for a new ECU I guess, but will get it performance tuned while I do it to include new 380cc injectors and a new cold air intake so if it doesn’t help the electrical problems it wont be a complete waste of money lol. Fortunately I bought it as a toy to play with so I don’t have to use it a daily driver. But wish I could get some play time with it instead of just working on it.

 

Since

 

I recently read about an alternator overcharging issue causing weird electrical problems. Have you tried pulling the voltage reading when the car is acting up with all the lights on?

 

I did check alternator voltage as I had read similar also, voltage with a digital meter remained at 14.6 with minimal fluctuation. Thanks for the suggestion!

 

Thanks for the suggestion. I removed the tach this evening hoping that could be the issue. Still experienced the same problems. I appreciate the response though, at this point I am Open to trying just about anything lol!

 

Mine had this issue and it was the alternator. However, mine was outputting 19VDC when this happened.

 

Well changed out ECU, immobilizer, and ignition key Cylinder with one from another R53 and no change. Running out of ideas.

 

are you able to monitor voltage while driving? maybe try an elm327 with the torque app

 

I know you replaced the alternator but what about unhooking it both the plug and big wire just for a short test drive to rule out any instability your meter may not pick up or a/c voltage that may be leaking through the diodes.

 

I would grab a DVM / multi-meter and check the input and output voltages at various critical components. I suspect a gremlin somewhere that’s causing crossed signals or a weak signal.