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Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Mazda
Satisfied Customers: 48323
Experience:  16 years of experience
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2003 6s AT. Has had drivability issues since new. Many times

Customer Question

2003 6s AT. Has had drivability issues since new. Many times to dealer with only response that no codes stored so must be ok. Many instances where the dash goes crazy while driving. TC light comes on. Gauges swing wildly (tach / spd). Almost as if it is rebooting. Transmission light comes on. Transmission shifting very erratic. It is fine, then starts "slam" shifting. Basically will hesitate to shift into 2nd. Do this false neutral rpm rev, then slam into 2nd. Then almost immediately slam into 3rd. This leaves it in too high a gear. Can push the accelerator all the way down, but won't downshift. Also won't start when turn the key. As if Ignition relay not working. Replaced both ign switch and relay, but no help. If keep trying, or hold the key in the start position, eventually it will respond, the starter will activate and the car start.
JA: Are you hoping to fix this yourself?
Customer: Well, I have had 0 luck with the dealers (plural)
JA: Is there anything else important you think the Mazda Mechanic should know about your Mazda?
Customer: 150K miles, new battery, filters, etc.
JA: Lots of things can cause problems with the battery. The Mazda Mechanic will know what to do. Our top Mazda Mechanic is ready to take your case. Just pay the $5 fully refundable deposit and I'll fill the Mazda Mechanic in on everything we've discussed. You can go back and forth with the Mazda Mechanic until you're 100% satisfied. We guarantee it.
Submitted: 1 year ago.
Category: Mazda
Expert:  Eric replied 1 year ago.


I am sorry that you have not been helped yet. I just came online and saw your question.

Ok, it sounds like there may be an issue with either the input or output transmission speed sensor, but I need to get the 17 digit vin number to pull all the schematics

Customer: replied 1 year ago.
VIN: 1yvfp80dx35m38789
Would those sensors cause the dash to flip out, too. It actually will shut off the engine sometimes, and you have to restart it. Another symptom is that the throttle is wonky. More specifically, as you press the pedal down, power will build until you get to about 1/4 of the way down, then as you continue to depress the pedal, the power drops off. If you back off the pedal, the power will build, again.
Customer: replied 1 year ago.
BTW: wife is a major back seat driver. When I come up on someone and let off the gas (and the power builds = accelerates) she always flips out.
Expert:  Eric replied 1 year ago.


Ok, that sounds more like either a computer issue or possible ground but to be honest, with this many issues, I would need to do some hands on testing. I am going to opt out and see if another expert has encountered this and knows the exact issue without need for hands on testing

Customer: replied 1 year ago.
Thanks. I appreciate that you are willing to reach out to others, as well.Side note: I had a bike (V45 Sabre) years ago that had drivability issues that were never resolved. One day while I had the fairing off, I disassembled the dash to get to the wiring for the headlight, and I noticed that the ground to the ignition had a cold solder joint. I resoldered it and it ran like a dream after that. That had been that way since new. So I can understand how that could be a possibility here. Could cause the "reboot" effect, etc. Any particular place to "start" looking? Is this where I need to get a hold of a wiring diagram and get my meter out?Another side note: Back in the mid 80's, I had a Chevy that had almost the same symptoms as this Mazda. Many times back to the dealer. No codes stored, or codes automatically cleared. They ultimately sent me home with this gadget plugged into the ODB2 port. It recorded on a loop and had a button on it that would save the last 60 seconds or so of data. They told me to press the button when the car was acting up. Did so, and when I took it back to them they said the ECU was bad. Replaced it, and again, better than new. So I can see how this could be the issue as well. This is actually more what I suspected, but I didn't want to include any diagnoses, just symptoms, as I didn't want to prejudice your line of thinking. Does Mazda (Ford?) have a similar recording device? (I can see how the ground issue might be a cheaper repair to start with, though.)Sometimes I miss the old days before electonics...
Expert:  Chris (aka- Moose) replied 1 year ago.

Welcome, I'm Chris (aka Moose). Experts aren't employees / agents of Just Answer. We are independent service providers using the Site to sell their Expert knowledge to Customers. I strive to provide EXCELLENT 5 STAR service to you, let me know what's needed from me so your pleased with my assistance and will rate me Good or Excellent.


The previous tech has opted out, would you like me to help?

Customer: replied 1 year ago.
Sure, I assume you have access to the rest of this thread. What do you think the first step should be. I picked up Torque & an adapter. Here are the scan results:Fault log report generated by Torque for Android
=================================================Vehicle VIN: 1YVFP80DX35M38789
Vehicle Manufacturer: Mazda
Vehicle Calibration ID: AJ58ET0B0ACurrent Fault Log
P0441: Evaporative Emission Control System Incorrect Purge Flow
U0100: Unknown code - More information may be available on the webPending Fault Log
ECU reports no pending faultsHistoric Fault Log
ECU reports no historic faults
Other discovered fault codes
(possibly pending, current or manufacturer specific)
U1900: Unknown code - More information may be available on the webEnd of report.
Expert:  Chris (aka- Moose) replied 1 year ago.

Thanks, ***** ***** EVAP code I suggest following the TSB sown below.

For the U codes I would disregard them. They are likely being caused by the scan tool your using not faults on the car.


On your screen you should see a rating 1-5 stars. Please make sure to select one. I am not compensated by the website unless a customer rates. Rating only pays me from the deposit you have already made, it does not charge you more, nor close the post. Also all follow ups are free and welcome.

Thanks Chris

Expert:  Chris (aka- Moose) replied 1 year ago.

Hello again Chris here,

1) When customers come to Just Answer the website and the experts want them to have a great 5 star experience.

2) We also want them to be so pleased that they come back for future needs.

3) I have the feeling you were not pleased with my help and or need me to help more. If so please do reply.

4) I have an option to upload diagrams, repair guides, find a repair facility, or call you if that would help.

Thanks Chris

Customer: replied 1 year ago.
Hi Chris,Thanks for the response. I am not as concerned about the Evap code as I am about the electrical gremlins. But next weekend I will replace the Purge Valve. That should take care of the code.My main concern is whatever is causing the drivability issues. Please review this thread, again. The only code that the dealer has ever found when the check engine light was on has been the evap code. So far, it has been resolved by removing the gas cap and putting it back. But they have insisted that there have been no other codes present. (do you have access to the vehicle history?)In 2012 I finally gave up on the dealer and took the car in to a Transmission shop because of the slam shifting and false neutrals. (Again dealer insisted that nothing wrong with the car) The Trans shop replaced the transmission (far from cheap). It seemed to help, but had no impact on the hesitation / acceleration issues. Since then the slam shifting has returned.So I took the car back to the Trans shop this Wednesday and left it. They believe that the shift solenoids are sticking and to blame. There is also a leak from the trans coolant lines. All in all they are talking $800+ to repair everything. They will have the car until next weekend (trans lines seem to be rare), therefore, the purge valve will have to wait until then.In the meantime, when the dash freaks out during driving it usually terminates with the traction control & transmission lights illuminated. Check engine light is not usually on, but it seems to be in some kind of limp home mode. When you turn the car off, then back on, everything seems back to normal.The latest has been that the car doesn't want to start. You turn the key, the dash cycles, but when you turn it to the start position, nothing happens. (like if it isn't in park or neutral) Even tried moving trans to neutral, but same thing. If you keep trying the key (sometimes 2, sometimes 20 times) it will eventually start as if nothing was wrong. However, if it it takes like 20 tries, it tends to die about 15/20 seconds into driving. Then it takes a bunch more tries to get it to start again. (meanwhile you are now sitting in the road) So last weekend, I replaced both the ignition switch (the actual electronic part on the left side of the steering column) and the ignition relay in the relay box under the hood. No help. Still exhibits the same behavior.So, if you think there is a questionable ground, somewhere, I am more than happy to get out the multimeter and look for it. I am guessing that it is not as simple as the ground cable on the battery, because the radio does not lose its stations when it happens. So where do you suggest I start looking?
Expert:  Chris (aka- Moose) replied 1 year ago.

I did not realize there were alot more issues than the EVAP concern. We are only permitted to help diagnose and fix one vehicle concern per post. For multiple issue the website wants customers to sign up for a subscription and open a new post for each issue. I can opt out and see if another does not mind breaking the rules and wants to tackle all these concerns on one post. I depend on this income and do not want to be banned from using the site. Would you like me to opt out?

Customer: replied 1 year ago.
Well, the evap is not what I opened this for. I have posted to this site looking for someone to help me track down the electrical issue. I have tried to provide as much history on this vehicle as possible, so that anything pertinent didn't get left out. I truly believe that there is some root electrical issue that is behind all the issues. I have turned to this site with the hope that someone here will be able to help me track it down.Since I have had this in to multiple dealers with no resolution, I understand that it must be quite a challenge. If you feel I would be better assisted by someone else, please feel free to forward it to another tech.
Expert:  Chris (aka- Moose) replied 1 year ago.

Opting out now.