Power Train Malfunction/Reduced Power Warning Light on 2011 CX-9

The wrench light is the powertrain malfunction/reduced power warning light. It could mean the engine's electrical system has a problem, the emission control system has a problem, the brake switch has a problem. In my case the dearler says it is the trottle control assembly. The part is on order and should be in tomorrow. I hope they are right.
 
Yesterday the dealer replaced the throttle body assembly om my new(766 miles) CX-9 due to the wrench warning light and loss of power problem. Today, with a warm engine the wrench came back on, no power. Had to turn the engine off and back on for it to work. Drove it to the dealer, they gave me a loaner car until they can figure out what is causing this problem. They did say they have to go toa reginal tech since they have no idea what the problem is. This is strike #2. One more try to become a lemon. I do love this car and hope they can fix it.
 
Yesterday the dealer replaced the throttle body assembly om my new(766 miles) CX-9 due to the wrench warning light and loss of power problem. Today, with a warm engine the wrench came back on, no power. Had to turn the engine off and back on for it to work. Drove it to the dealer, they gave me a loaner car until they can figure out what is causing this problem. They did say they have to go toa reginal tech since they have no idea what the problem is. This is strike #2. One more try to become a lemon. I do love this car and hope they can fix it.
Looks like the throttle body was not at fault after all...
 
I had a talk with my long time mechanic about the wrench code and loss of power to get his opinion as to what the problem maybe. He said it's a wire connection problem. A corroded or loose wire somewhere. He said he doubts that the dealer will ever find the problem and that I will have to invoke the lemon law to get a new CX-9. Based on what I have read so far, I think he's right.
 
I think that conclusion may be jumping the gun a little, just give them some time. If they replace say 3 or more things and you still have the light come on, then it might be time to think about a "lemon."
 
Unfortunately it only takes one bad part to cause these headaches. Just think about it. There are miles of wire and a ton of sensors and connections. Those molex connectors have wires inserted in them by machine. If one of those contacts is defective then you get gremlins like this. My guess is that there are parts of particular lot that have the issue. Have the two guys with 2011 compared VIN numbers? Based on the random nature of the problem I'm guessing this is a wire harness issue. BTW, my Mz6 sGT had the Throttle body issue and it manifested itself as a irratic idle. I never got a fault code. Then again it may depend on how far gone the Throttle body is. In my case I went along for a month or so before it got fixed. But the car was always reliable. And ironically showed no symptoms beyond the irratic idle. The tech who worked on it said that the fuel system was actually working perfectly from a measurement point of view.

BTW Helbigtw VIN range isn't a "load of crap" If Mazda's inventory control system is accurate it should match the VIN to the daycode (of whatever part identification they use) of particular parts to the defect. If they can track down the particular daycode of parts then they can single out the lot where the manufacturing defect is. Manufacturers typically don't handcheck parts that come in, they may do a spot check of a particular lot of parts but overall they rely on the supplier for extensive QC. Once the part get's installed in a product its checked as part of the whole system, not on it's own. A marginal part could check fine during final QC but then work it's way to bad during the shipping or once the product is actively used (i.e. multiple temperature cycles on the part).

This sort of process is pretty common across all modern manufacturing. The only difference is how up to date and accurate the parts inventory and manufacturing tracking system is. But my guess is that Mazda's systems are pretty up to date and accurate.
 
Last edited:
Let me re-phrase: You have a specified part on a specified vehicle which is failing, across the board on a majority of the vehicles, documented across all vin ranges, and the manufacturer states only a portion of these vehicles falls into the "vin range." Believe it or don't believe it, I'm just stating the facts.
 
I would love nothing more then for these guys to find the problem with my car. I will give them all the time they need to find the fix. I just want to get my car back and have trust in it.

The VIN # is JM3TB3DV4B0327915 for compairason. The code that the car gave was 123 which came back as throttle position sensor voltage not charging. They changed the throttle body, but did not fix the problem. I also think a wire assemble could be a problem, just hoping for a fix.
 
from that perspective, it does sound like either the engine control module, the engine wiring harness, or possibly something in a fuse block, whether it be a relay, the actual fuse block, or who knows. Good luck!
 
OK, I misread the post. Apologies :-). Yeah a "portion" seems to be a bit weird unless there was some manufacturing hold after the faulty part was found and then they slipped the new part into production. In that case though I would expect the VIN to be modified to indicate the new change. Although I'm not sure how Mazda flags a live manufacturing change. Maybe a case of major and minor part changes. Though a TB seems pretty major to me.

Money says it's a bad harness... :-)
 
Last edited:
Ever since my vehicle was returned since they were not able to recreate the issue, Ive only had it happen twice. It hasn't reoccurred at all in the last 2 weeks. I tried thinking what was different and the weather here in MN has changed. The wrench typically went on when the weather was between 40-60 degrees. The last 2 weeks it has been around 70-85. Maybe just a coincidence. Anyways my VIN is JM3TB3DA8B0328546.
 
Today Mazda is installing a new engine wire harness. I'm keeping my fingers crossed that this will take care of the wrench malfunction.
 
The dealer has replaced the wire harness and so far the wrench malfunction code has NOT reappeared. It seems to have corrected the problem. Apparently it was a wire problem that was related to the wire harness. I'm so glade because I really love this car.
 
Glad to hear it is fixed. Make sure you look the entire engine bay over really well. Even the best of technicians take shortcuts i.e. using tape and zip ties rather than factory clips, brackets & braces for the harness. Also look for damaged component connectors on the component side i.e. the electrical connector on the a/c compressor, or electrical connectors attached to the alternator, etc. It would be difficult to replace an entire engine wiring harness without causing more minor damage to other stuff. I see this all the time in the collision industry done by A techs. (technicians who are top notch as opposed to B or C techs)
 
Exact same thing happened to my cx9. The dealer changed the throttle module first but that did not fix it. They changed the engine harness and the car has been running fine for months. In my case, it should be some wiring issue in the harness which caused low voltage on the throttle module.

The dealer has replaced the wire harness and so far the wrench malfunction code has NOT reappeared. It seems to have corrected the problem. Apparently it was a wire problem that was related to the wire harness. I'm so glade because I really love this car.
 
Back