On Board Diagnostic (OBD) System of A/T and Engine
Precautions for On Board Diagnostic (OBD) System of A/T and Engine
The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the driver of a malfunction causing emission deterioration.
CAUTION: Be sure to turn the ignition switch OFF and disconnect the negative battery terminal before any repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves, etc. will cause the MIL to light up.
Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will cause the MIL to light up due to an open circuit. (Be sure the connector is free from water, grease, dirt, bent terminals, etc.)
Be sure to route and secure the harnesses properly after work. Interference of the harness with a bracket, etc. may cause the MIL to light up due to a short circuit.
Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube may cause the MIL to light up due to a malfunction of the fuel injection system, etc.
Be sure to erase the unnecessary malfunction information (repairs completed) from the TCM or ECM before returning the vehicle to the customer.
Precautions
Before connecting or disconnecting the TCM harness connector, turn ignition switch OFF and disconnect negative battery terminal. Failure to do so may damage the TCM. Because battery voltage is applied to TCM even of ignition switch is turned off.
When connecting or disconnecting pin connectors into or from TCM, take care not to damage pin terminals (bend or break).
Make sure that there are not any bends or breaks on TCM pin terminal, when connecting pin connectors.
Before replacing TCM, perform TCM input/output signal inspection and make sure whether TCM functions properly or not.
After performing each TROUBLE DIAGNOSIS, perform "DTC (Diagnostic Trouble Code) CONFIRMATION PROCEDURE".
The DTC should not be displayed in the "DTC CONFIRMATION PROCEDURE" if the repair is completed.
Before proceeding with disassembly, thoroughly clean the outside of the transaxle. It is important to prevent the internal parts from becoming contaminated by dirt or other foreign matter.
Disassembly should be done in a clean work area.
Use lint-free cloth or towels for wiping parts clean. Common shop rags can leave fibers that could interfere with the operation of the transaxle.
Place disassembled parts in order for easier and proper assembly.
All parts should be carefully cleaned with a general purpose, nonflammable solvent before inspection or reassembly
Gaskets, seals and O-rings should be replaced any time the transaxle is disassembled.
It is very important to perform functional tests whenever they are indicated.
The valve body contains precision parts and requires extreme care when parts are removed and serviced. Place disassembled valve body parts in order for easier and proper assembly. Care will also prevent springs and small parts from becoming scattered or lost.
Properly installed valves, sleeves, plugs, etc. will slide along bores in valve body under their own weight.
Before assembly, apply a coat of recommended ATF to all parts. Apply petroleum jelly to protect O-rings and seals, or hold bearings and washers in place during assembly. Do not use grease.
Extreme care should be taken to avoid damage to O-rings, seals and gaskets when assembling.
Replace ATF cooler if excessive foreign material is found in oil pan or clogging strainer.
After overhaul, refill the transaxle with new ATF.
When the A/T drain plug is removed, only some of the fluid is drained. Old A/T fluid will remain in torque converter and ATF cooling system.
Always follow the procedures under "Changing A/T Fluid" when changing A/T fluid.