What is very clear. Oxidation on wire housing pins, contacts, wire lugs, even in wire sheathing between strains of wires. Increases resistance between signal source and point relying on specific signal/current. Which will, result in functional issue. We've seen examples of this often, in 100 series tech section.
What is not as clear. Would this GOO or even just used ATF, effect current flow. Between pins in a wire housing block and or wire strains. When we assume high mileage ATF, has more insoluble the higher the mileage and or more hard/heavy use on A/T. Insoluble like: Iron, copper, boron, magnesium, aluminum, zinc & lead. A.I says YES:
A.I. Summary
The condition you described would definitely affect electrical performance. The primary result would be increased resistance and potential signal interference or loss due to the contaminated fluid creating poor contact points, rather than a direct short circuit. This is a known issue with some vehicles (e.g., Mercedes-Benz 722.6 transmission) where fluid wicks into the harness, necessitating cleaning and replacement of connectors.
A.I. ?
Would automatic Transmission (A/T) fluid (ATF), with 150,000 miles of use. Which has some insoluble, like iron & lead in ATF, due to wear within A/T. That by capillary action wicked through wire sheathing and between strains of wires within. Then into wire housing block on outside of A/T. Then mixed with dielectric grease, within a wire housing block. Mixture then getting between connecting pins within the wire housing block. Which wire harness and wire housing block. Would also be subjected to heating and cooling cycles. From -10F to 200f. Affect current flow, between TCM/ECM and solenoids. Perhaps increase resistance in wires and or result in cross current between connecting pins?
Yes, used automatic transmission fluid (ATF) with wear particles wicked into a wiring harness and connector block would likely affect current flow, resulting in increased resistance and potential signal issues, but is less likely to cause a direct "cross current" in the traditional sense.
Here is a breakdown of why this would cause problems:
1. Increased Resistance
Contamination: While new, clean ATF is an excellent insulator (a dielectric fluid), used ATF contains polar additives and, critically, metallic wear particles (iron, lead, etc.) and oxidation byproducts. These contaminants make the fluid more conductive (or less insulating) than clean oil, especially when mixed with dielectric grease, which is also an insulator.
The resulting mixture in the connector is a foreign substance at the contact point.
Reduced Contact Area: The primary issue is the physical presence of this contaminated mixture between the connecting pins. The fluid film and trapped metal particles act as a barrier or create poor contact points, reducing the effective metal-to-metal contact area of the pins.
Corrosion/Degradation: The presence of contaminants and the heat cycling can promote oxidation or corrosion of the metal terminals over time, which significantly increases contact resistance.
Signal Integrity: Increased resistance at connection points can lead to faulty signal readings or even signal loss, which would directly impact the communication between the TCM/ECM and the solenoids, affecting transmission operation.
2. Heating and Cooling Cycles
The repeated heating and cooling cycles from -10°F to 200°F would exacerbate the problem:
Expansion and Contraction: Thermal cycling causes the materials (pins, plastic housing, fluid) to expand and contract at different rates. This constant movement can physically dislodge terminals, further degrade the contact points, and help the fluid migrate deeper into the harness and connector.
Viscosity Changes: The viscosity of the fluid changes with temperature. At higher temperatures (200°F), the fluid is less viscous and can more easily flow or spread across surfaces, potentially reaching more pin interfaces.
Accelerated Degradation: High temperatures accelerate chemical reactions, including the oxidation of the oil and the corrosion of the metal components, worsening the overall contamination and resistance over time.
3. Cross Current/Short Circuit Risk
While pure, new ATF is a good insulator, the used, contaminated mixture is less so.
Conductive Path: If enough metallic particles accumulate to form a continuous, low-resistance path between adjacent pins, a cross-current (or short circuit) could theoretically occur. However, the fluid and grease generally remain somewhat insulating, making a hard short less likely than simply high resistance.
Capacitance Issues: The difference in the electrical properties (permittivity) of the oil/grease mixture compared to air can also affect high-frequency digital signals by increasing cross-talk capacitance, which could also cause intermittent signal problems.
Summary
The condition you described would definitely affect electrical performance. The primary result would be increased resistance and potential signal interference or loss due to the contaminated fluid creating poor contact points, rather than a direct short circuit. This is a known issue with some vehicles (e.g., Mercedes-Benz 722.6 transmission) where fluid wicks into the harness, necessitating cleaning and replacement of connectors.
Here's Blackstone report. ~170K miles ATF, was not sampled. First sample taken, was on ~5K miles after a 12 qt ATF flush at ~170K mile. It began very noticeable shifting issues, few hundred miles before sample taken. Second sample was ~440 miles after fresh 12qt ATF flush and inline filter added. OP wire housing block with GOO, is from same vehicle.
lol
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Based on the few cases here in this thread, NOW!
