General Description
A/T Diagnosis General DescriptionThis vehicle is equipped with an electronic transaxle control system, which controls the automatic shift up and shift down timing, TCC operation, etc. suitably to vehicle driving conditions.
TCM has an On-Board Diagnosis System which detects a malfunction in this system and abnormality of those parts that influence the engine exhaust emission.
When diagnosing a trouble in transaxle including this system, be sure to have full understanding of the outline of "On Board Diagnostic System Description: - and each item in "Precautions in Diagnosing Trouble:" and execute diagnosis according to "A/T System Check:" to obtain correct result smoothly.
On-Board Diagnostic System Description
For automatic transaxle control system, TCM has following functions.
^ When TCM detects a malfunction in A/T control system, it stores malfunction DTC and at the same time transmits DTC of that malfunction to ECM. (Based on this signal, ECM turns ON malfunction indicator lamp (MIL) (1) and stores DTC/freeze frame data in its memory.)
^ If no malfunction is detected after detecting malfunction, TCM immediately halts to transmit DTC of that malfunction to ECM, however, DTC stored in TCM memory will remain. If ECM receives no DTC of malfunction for 3 driving cycles continuously, it turns MIL off although DTC stored in ECM memory will also remain.
^ It is possible to communicate with ECM and/or TCM through data link connector (DLC) (2) by using SUZUKI scan tool (3). (Diagnostic information can be checked and erased by using scan tool.)
^ It is also possible to check DTC stored in TCM memory by displaying DTC on digital display odometer (5). DTC is displayed on odometer by connecting diagnosis switch terminal (7) with ground terminal (8) of monitor connector (color in Blue) (6), with reset button (4) pressed. If no malfunction DTC is stored in TCM memory, DTC No. 12 is displayed. If one or more DTCs are stored in TCM memory, they are displayed 3 seconds each sequentially. After all DTCs are displayed, they are displayed in the same manner again.
2 Driving Cycle Detection Logic
When a malfunction is detected during initial driving cycle, TCM transmits a data to inform ECM of malfunction occurrence. At this time, ECM stores a corresponding pending DTC in its memory. (but MIL does not light). If the same malfunction is also detected in next driving cycle, ECM lights MIL when it receives a data informing occurrence of a malfunction from TCM.
Freeze Frame Data
Refer to "Engine System Check:".
Precautions in Diagnosing Trouble
^ Don't disconnect couplers from TCM and/or ECM, battery cable from battery, TCM and/or ECM ground wire harness from engine or main fuse before checking the diagnosis information (DTC, freeze frame data, etc.) stored in TCM and/or ECM memory. Such disconnection will clear memorized information in TCM and/or ECM memory.
^ Using SUZUKI scan tool the diagnostic information stored in ECM memory can be checked and cleared as well. Before its use, be sure to read Operator's (instruction) Manual supplied with it carefully to have good understanding of its functions and usage.
^ DTC stored in TCM can not be cleared by using ECM application of SUZUKI scan tool in mass storage cartridge. Be sure to follow" DTC Clearance:" when cleaning it.
^ Priorities for diagnosing troubles
If two or more diagnostic trouble codes (DTCs) are stored, proceed to flow table (chart) of DTC, which was detected earliest in order and follow instruction in that table (chart). If no instructions are given, troubleshoot diagnostic trouble codes according to the following priorities.
1. Diagnostic trouble codes (DTCs) other than "DTC P0171/P0172: Fuel System Too Lean/Rich (Bank-1):", "DTC P0300/P0301/P0302/P0303/P0304: Random/Cylinder 1/Cylinder 2/Cylinder 3/Cylinder 4 Misfire Detected:", "DTC P0401/P0402: Exhaust Gas Recirculation (EGR) Flow Insufficient/Excessive Detected:" and" DTC P0403: Exhaust Gas Recirculation (EGR) Control Circuit:"
2. DTC P0171/P0172 (Fuel system too lean/too rich) and DTC P0401/P0402/P0403 (EGR flow malfunction)
3. "DTC P0300/P0301/P0302/P0303/P0304: Random/Cylinder 1/Cylinder 2/Cylinder 3/Cylinder 4 Misfire Detected:
^ Be sure to read "Precautions for Electrical Circuit Service:" before inspection and observe what is written there.
^ TCM and/or ECM replacement When substituting a known-good TCM and/or ECM, check for following conditions. Neglecting this check may result in damage to good TCM and/or ECM.
- All relays and actuators have resistance of specified value.
- MAP sensor and TP sensor are in good condition. Also, the power circuit of these sensors is not shorted to the ground.