Luck, Or Just Good Business?
Mazda Protégé Shifting Problems

What if someone showed up to your shop complaining of incorrect shift points, excessive shift shock, an O/D OFF indicator light flashing and a malfunction indicator lamp (MIL) illuminated? You would probably say to yourself, "Man, this transmission is messed up. This definitely won't be easy to fix. There's so much wrong with it."

I remember one busy afternoon, a young man named Greg stopped by the shop and was complaining about the exact problem I just described.

When I met him out on the service drive, he gave me a detailed description of the problem and seemed genuinely concerned with the fate of his little car. "I hope this isn't too serious," he said. "My dad will kill me if I wrecked the transmission." I wasn't sure how someone could inflict so much damage, but I reassured him that it probably wasn't his fault, and maybe, it was something really simple. As I drove the car around the block to verify his concerns, I chuckled to myself, "I hope it's simple for your sake, kid."

 

I brought his ailing '95 Protégé® into the shop and connected the scan tool to find out why the MIL was on. A code "P0711" was produced, which indicated that the transaxle fluid temperature sensor had malfunctioned. The next step was to check for a technical service bulletin (TSB) on my ALLDATA® information system that might shed some light on this problem. It's a good thing I did.

This was Greg's lucky day. I found a TSB that described his symptoms to a tee. The TSB explained that on some 1995 to 1998 Mazda® Protégé® and 1992 to 1995 MX-3® models, a metal retaining clip could pinch the valve body harness for the transaxle fluid temperature sensor. This could cause a short or open circuit.

The following diagnostic and repair procedure was outlined in the TSB:

1. Verify the customer's complaint.

2. Remove the intake air-hose and disconnect the solenoid connector.

 

3. At the valve body harness (transmission side), measure the resistance across the terminals as shown.

5. Check for continuity between each terminal and the transaxle case.

6. Remove the transaxle oil pan. Inspect the transaxle fluid temperature sensor wires for shorts against the metal clip. If the wires are exposed due to the insulation being worn away at the clip, repair the wire (s) and wind the newly established part (tube) around the damaged location. Then, confirm there is no continuity between each terminal and the transaxle case. Make sure that the protective tube is installed under the metal clip.

Updated Harness Application Table

7. If necessary, install an updated solenoid valve body harness (coupler) using the following steps.

I finished the job in about two hours, took the car out for a test drive and all was back to normal. Greg's dad accompanied him when he came to pick up the car. "You know," he said, "Greg had this car to a shop across town and they gave him an estimate for a new transaxle," he said. "It's great to find a trustworthy shop that takes the time to diagnose a problem completely." "Well, thanks." I replied. "We pride ourselves on being an honest, professional shop. There are plenty of broken vehicles out there that need legitimate repairs."

Smiling, Greg's dad offered, "Speaking of broken vehicles, I own a delivery business with a fleet of about 50 cars and trucks. I'd like your shop to maintain and repair them." Needless to say, Greg wasn't the only lucky one that day.