Visual/Physical Underhood Inspection

GENERAL DIAGNOSTIC INFORMATION VISUAL/PHYSICAL UNDERHOOD INSPECTION
A careful visual and physical underhood inspection must be performed as part of any diagnostic procedure or in finding the cause of a failure. This can often lead to fixing a problem without further steps. Inspect all wires in engine compartment for proper connections, burned or chafed spots, pinched wires, contact with sharp edges or hot exhaust manifolds. This visual/physical inspection is very important. It must be done carefully and thoroughly.

KNOWLEDGE AND TOOLS REQUIRED
To use this most effectively, a general understanding of basic electrical circuits and circuit testing tools is required. One should be familiar with wiring diagrams, the meaning of voltage, ohms, amps, the basic theory of electricity, and understand what happens in an open or shorted wire.
To perform system diagnosis, the use of a diagnostic Scan tool is required. A tachometer, test light, digital ohmmeter with 10 megohms impedance, vacuum gauge, and jumper wires are also required. Please become acquainted with the tools and their use before attempting to diagnose a vehicle.

RESETTING TRANSAXLE OIL LIFE
In the unlikely event a vehicle comes in with a transaxle control module (TCM) or engine control module (ECM) that cannot be read with the Tech 2, follow this procedure to set the transaxle oil life remaining in the new ECM/TCM.
1. Interview the customer to determine vehicle usage (vehicle used for towing, towing of what, how often, on what terrain: flat, hilly, mountainous, city or highway, etc.). Use this information to determine severe or normal usage.
2. Check fluid level in transaxle. After removing the transaxle fluid level plug, a small amount of fluid may come out of the opening. If no fluid comes out, use a turkey baster to remove a small amount of fluid. Inspect fluid condition (smell, color).
3. Record vehicle mileage.
^ If vehicle usage is determined to be normal. and fluid condition is normal, use vehicle mileage to set transaxle oil life remaining. Example: 50,000 miles, set oil life remaining to 50±. At 70,000 miles, set oil life remaining to 30%.
^ If vehicle usage is determined to be severe, and fluid is discolored/smells burnt, recommend fluid and filter change and set oil life remaining to 100%.
^ If vehicle usage is determined to be normal, fluid condition is normal, and vehicle has over 80,000 miles, recommended fluid and filter change and set oil life remaining to 100%.
Fluid condition should be the main factor in determining oil life remaining, followed by vehicle usage and mileage.
Normal Fluid: Use vehicle mileage as determining factor.
Burnt/Smelly Fluid: Recommended fluid and filter change, reset oil life remaining to 100%
Burnt/Smelly Fluid with No Fluid Change: Use vehicle mileage as determining factor.

REPAIR VERIFICATION
After making a repair to the transaxle it is "important the repair is verified before returning the vehicle to the customer. The vehicle must be driven so that each upshift and downshift is accomplished at least twice, and then the ECM/TCM must be checked for diagnostic trouble codes. Not all faults will illuminate an indicator lamp and the memory must be checked when using a Scan tool.