This 2004 Mazda Tribute came in with the complaint that engine stalls when the transmission is placed into drive. It also stalls when coming to a stop. It does not stall in reverse or neutral. Checking codes found a code P0320 stored for a crank sensor fault. As most of you should know a Mazda Tribute, Ford Escape and Mercury Mariner are all the same vehicle. So this problem and repair apply to all three over various years with the V6 engine.
Dropping a splash shield found that the crank sensor has already been replaced.
I did take the time to inspect the harness connector for loose terminal fit and any wiring problems in the general area. None were found.
I looked closely at the engine compartment harnesses while someone else shifted the transmission between reverse and drive and back again. I saw where the engine harness flexed substantially. It was between the top rear of the engine and where the PCM is mounted in the firewall, above the engine.
I had to remove the tape around the split loom so that I could open up the harness. After looking at a wiring diagram I knew that I would be looking for problems on either the black/pink wire @ terminal 21 or the gray/yellow wire @ terminal 22. When I pulled both wires out of the 104 pin PCM harness connector the problem was obvious. The bend in the black/pink wire indicated an internal break.
Pulling on the wire also showed that the wire was broken inside the insulation. The insulation would stretch and change color when pulled on.
A local salvage yard supplied a used 104 pin PCM harness so that I could splice in a replacement for the damaged wire. There are four locking tabs that have to be released in order to remove the black strain relief cover.
The red terminal positive assurance clip can be removed as shown below.
Using an angled pick the internal terminal retainer can be moved, so that the wire and terminal can be pulled out of the harness connector body.
The long edge of the pick has to be slid down the side of the terminal that is being removed. It will stop on the edge of the internal plastic retainer and the plastic retainer then has to be flexed away from the terminal. The wire and terminal needs to be gently pulled at the same time to keep the terminal unlocked from the housing.
The wire and terminal pull out of the connector body as shown below.
The terminal holes are numbered on the rear outer edges of the gray harness connector body.
The wire repaired and back in the harness. I replaced the wire with a longer piece of wire so that the splice joint would not be at the previous position of highest flexing. Had I not moved it away, it would have broken again in a short time. Note that the two wires are in what is referred to as a twisted pair and that I maintained the twist in the repair.
I also re wrapped the metal tape around the twisted pair.
I finished by reinstalling the split loom and wrapping it with electrical tape. Then I secured it all to the black strain relief cover on the PCM harness connector.
I strongly encouraged the owner to have the motor and transmission mounts replaced. They were worn and were the primary cause of the harness failure.