Alex_3112

I have 2007 RDX, 110K Miles, dealer serviced, never a problem until now. After my latest service (with brakes replaced) I found two strangely interconnected issues that are progressively getting worse.

1. Transmission. Sometimes, when coming after a stop, the car acts like it's almost on Neutral. I press the gas, engine roars, but acceleration is anemic. Tachometer shows 3000 rpm, no more, turbo may go all the way up. After some time car is able to pick up some speed, and then, with a violent jerk, transmission shifts to a higher gear and car jumps forward, like it should. When this happens, I'm able to flip gearstick to "neutral", then back to "drive", which fixes the problem.

2. Navigation. Sometimes, navigation system spontaneously reboots. More rarely, reboots will happen in a non-stop loop. During the reboot, all other car electronics is working well, only couple of times I had the radio paused as well.

These two problems are clearly connected with braking, or maybe driving at very slow speed. Cruising at high speed, even with road bumps, does not affect the navigation at all, but if I dare to break to a stop, navigation will likely to go dark that very instant, and transmission problem is ready to follow.

Because these problems are intermittent, my dealer has a difficulty to diagnose. They are talking about replacing the whole transmission and navigation unit.

Any ideas?

dcmodels

As you note, intermittent problems are always difficult to diagnose, esp. online without access to your vehicle. Anyhow, both problems could be electrically related, and unrelated (except by coincidence) to your brakes. So start with the obvious ...

Have the battery tested. I have had really strange problems with various vehicles, when the battery is weak/ needs replacement. Battery should be both load tested, and tested after sitting overnight that it reads 12.4 volts (MINIMUM) at the battery itself, across the plus/ ground terminals.

Most battery load testers will also check the voltage. But make certain that the load test is performed at the correct load for your battery, generally 1/2 the CCA (cold cranking amps). Hopefully the person performing the test will do it correctly. I have had someone at the local part store, who will do the test for 'free', incorrectly perform the test ( to sell a battery I assume). The idiot at Sears seemed to do it correctly, just did not let me watch so that I could verify his report.

My Acura dealer will also perform a battery load test. Again, the problem is if the battery is hot, like you have been driving 20 miles, the test may not be valid.

A fully charged battery should read 12.65v with a digital voltmeter. Less than 12.4 volts is only about 60% charged, at which point you will definitely begin to have problems.

These readings are to be taken at 80degrees. The battery will read a lower voltage at a higher temp, and higher voltage at a lower temp, but not enough to matter. That is only true if the battery is at the air ambient temp, that is, it has been sitting overnight and the vehicle has not been driven (so that the engine bay is not hot).

Oh, and once I had problems because the battery cables had worked loose. Talk about intermittent problems ...

Let us know what you find, when finally diagnosed.

Alex_3112

I am happy to report that all my problems are fixed now. Last time I took the the car to dealer, I asked them to check wiring. And voila - they found a bad bolt that was responsible for connecting some grounding wire to the body. They replaced it, and both transmission and navigation are fine now. Moreover, for a total of three days that my car was in the shop and I used their loaners, I didn't have to pay a dime.

Thanks everybody!