This Mazda check engine light article pulls information from a technical service bulletin that was issued back in 2003. It applies specifically to 2001 through 2004 Mazda MPV multipurpose vehicles. This is of course Mazda’s term for minivan.
The bulletin specifically talks about a check engine light illuminated and storing a trouble code of P0706 which is a transmission code. If you are interested in finding specific technical service bulletins for your exact year make and model of Mazda car or truck you can obtain these for a minimal expense from web based auto repair guides.
The bulletin number I’m discussing today is 01-023/03. It explains that some of the affected vehicles may either turn on the check engine light or the overdrive light indicator could be flashing indicating a stored code of P0706 stored in memory. This condition may be caused by the gear shift lever being placed between drive and the number three range position.
This can cause the signal from the inhibitor switch to be disrupted temporarily. Because of this the transmission control module (TCM) can provide a false indication of a faulty inhibitor switch. Mazda put the neutral safety function and the transmission range function all together and call it an inhibitor switch. It stops it from starting in neutral and park.
Repairing the Mazda MPV Set Codes
If the Mazda check engine light is illuminated connect a scan tool and verify a set code of the P0706. You don’t need a fancy scanner. You can read and clear the check engine light set codes with basic scan tools like the actron 9550 pocket scan tool.
The Technical service bulletin outlines the procedure to readjust the inhibitor switch so that this intermittent fault does not recur and turn the Mazda check engine light back on. Unfortunately you have to remove the battery and the battery tray to gain access to the transmission range switch which they call the inhibitor.
You can use a set of jumper wires and or cables to connect the battery to the vehicle so that you can properly adjust the range switch signal. Make double sure that the jumper wires or cables that you use are hooked up correctly to the battery otherwise damage could occur to the vehicle systems and modules.
With the Battery connected but out of the vehicle, Turn the ignition key to on and then move the shift lever between the drive and number three positions until the black box outlined around the D in the shift indicator goes off and hold the shift lever in this exact position. An assistant may be needed to hold the shift lever while inhibitor switch adjustments are made.
Next you loosen the inhibitor switch bolts and slowly turn the inhibitor switch counterclockwise until the black box outlined turns back on around the “D” in the shift indicator. It’s nice to have an assistant in the driver seat watching the shift indicator. Have them give you thumbs up when the black box returns around the letter D.
Next you lock down the retaining bolts to hold the inhibitor switch firmly in place. Then operate the shift lever and confirmed that the range signal outline box is on for each designated range position as Mazda intended.
Then you can disconnect your jumper wires and reinstall the battery tray and then the battery. The last step in this Mazda check engine light repair procedure is to verify that the vehicle will only start in the park and neutral ranges.
Again the range indicator switch or inhibitor switch has a built-in function that a separate neutral safety switch would handle. You do not want your vehicle to start in drive or reverse as injury could occur. You may find it necessary to connect the scan tool to clear out any codes that were set during the adjustment procedure.
This was a technical service bulletin sent to me as a Mazda technician way back in 2003. After performing this bulletin several times I was able to do it by myself, but an assistant makes things a lot easier.
Also remember the TSB were intended for professional technicians. If this is outside your skill level have it performed by a professional mechanic. I built a page all about these types of factory notifications. Here is a link to find out more about technical service bulletins. Give this page about Mazda check engine lights a bookmark or share.
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