TCS Off and Low Oil Pressure lit suddenly, dipstick shows oil OK

[tipo158]

I have a 2007 CX9 with 67000 more-or-less trouble-free miles on it.

Today, the Low Oil Pressure light, Brake light, the TCS Off light and the TSC/DSC Indicator light all lit up (and now stay lit) after driving the CX9 about a mile or so. Drove it back to the house where it has sit.

I checked the engine oil dipstick and there is sufficient oil in the engine.

Before this, my wife noticed a grinding noise from the left front, but the noise never showed itself to me.

Any ideas what is up?

I got the extended warranty, so I guess a trip to the dealer is in my future. However, the Thursday before Labor Day weekend isn't the best time to encounter a problem like this. As a side question, any recommendations for where in Puget Sound to have look at the car. I do most work on my cars myself.

alan

 

[tipo158]

The dash indicators for TCS Off, TCS/DCS, Brake and Low Oil still light up when I start the CX9. Now the power door locks have stopped working.

However, the engine runs fine. Oil looks good on the dipstick. Brake feel fine.

Obviously something is up with the electrics.

alan

 

[ceric]

You can go visit AutoZone or Kragen. They can use scanner to read out the codes.
Since there are lights, there are codes.

 

[DDDonkey]

I would check the battery, I have a vehicle do that once and it was the batteries.

 

[Kenundrum]

I had a similar thing happen about a month ago with my cx-9 while fiddling with sensor readouts from a Bluetooth scan tool. thankfully the scan tool was still able to tell me the error codes which indicated a loss of communication with the BCM. I was probably trying to pull too much data too quickly and crashed something. The error lights were on, windows didn't work, turn signals were dead, general weird electronics stuff. Manually clearing the error didn't fix anything. I tried disconnecting the battery for about 10 minutes and that did it. Unfortunately I had to reset the radio presets, window auto up/down and other stuff. I've always been told that if a problem is legitimate, after clearing codes the sensors will pick up on the problem later and throw another code.
It seemed to take care of my problem, but I knew it was self inflicted. For an issue that comes out of the blue like that, you probably want to have the codes read out to make sure it isn't anything actually critical and then try to clear them and see if they come back.

 

[Kenundrum]

Ironically, this happened to me just today and I've narrowed down the cause (at least for me). This happened to me while actively reading OBD data and turning the car off. I use a scantool paired to my phone to read out transmission temp and other info when I tow and I forgot to remove the OBD connector before shutting the car off. I had the same lights on as you mentioned and the specific code was U0140 Loss of communication with Body Control Module. What fixed it for me was turning the engine off, putting the key in the on position. Clearing the code, and then removing the OBD adapter and turning the engine on.

 

[tipo158]

Got a copy of the service manual over the weekend and have been going over and through things.

Battery and charging are fine. The grounds that I checked are fine.

My OBD scan tool reports no codes. Just because there are lights doesn't mean there are codes. The lights on the instrument cluster are pretty much all driven by the BCM via the CAN bus. The brake light can turn on because the BCM gets the signal from the handbrake switch and translates that into the appropriate CAN bus message for the instrument cluster; that doesn't throw a code. Similarly, the oil light and TCS lights can all be lit for conditions that don't throw codes.

I think that the problem is likely to be the BCM. A failure of the BCM is the only component tied into all of the failures that I have observed.

alan

 

[table5511]

I've ever had 2 incidents. 1 - Put driver window down on interstate and Blindspot indicator lamp illuminated on the driver mirror 2 - turned car on one time and tcs & another lamp illuminated. Turned car off, back on and problem went away.

Who knows?

 

[tipo158]

Took the CX-9 to the dealer yesterday. After looking at the logged errors, the tech asked if we jump started the car when the problems started. Nope.

The dealer consulted with Mazda and, based on the number of kinds of logged errors, they were asked to go through all of the relevant harnesses and control modules. Today they decided to replace the BCM. I am supposed to get the CX-9 back on Monday. Until then, I have a Mazda 6 loaner.

alan

 

[tipo158]

Here is an update. As noted, the problem was the BCM, which the dealer replaced under the extended warranty.

But ...

A week ago, the 4-way flashers turned on and would not turn off. I took the CX-9 to the dealer and they determined that it was another failed BCM. This time they had the culprit. There was water on the floor by the BCM. The problem was clogged sunroof drains and the water overflowing into the headliner, then down the a-pillar trim, then down the body onto the BCM. Unfortunately, because it was caused by water intrusion, it was not covered by the Mazda "TotalCare" extended warranty.

Doing more searches, I have found web reports of this happening at least as far back as 2010. I am miffed at Mazda over this. There is no factory-documented procedure for clearing the sunroof drains (that I know of). With critical electronic components in a natural flow path for water coming in from the sunroof, one would think that clearing the sunroof drains should be included in scheduled maintenance. Volkswagen had a recall and class action settlement over this exact same kind of problem a few years ago.

I have contacted Mazda USA. I recommend that, if you have a CX-9 with a sunroof, you keep an eye on the sunroof drains and where the water exits (behind the front wheel wells). Occasionally pour water into the sunroof drain and confirm that it comes out where it is supposed to.

alan