When the vehicle has one of these symptoms, check for a diagnostic trouble code (DTC) with the HDS. If there is no DTC, do the diagnostic procedure for the symptom, in the sequence listed, until you find the cause.

Symptom	Diagnostic procedure
HDS does not communicate with the TCM or the vehicle	Troubleshoot the DLC circuit; L13Z1 engine model, R18A2 engine model.
i-SHIFT indicator does not come on	1. 2.	Do the gauge control module troubleshooting. Check the i-SHIFT INDICATOR LIGHT F-CAN in the DATA LIST with the HDS. If it is NG, replace the TCM; L13Z1 engine model, R18A2 engine model.
i-SHIFT indicator stays on, but no DTCs are stored	Symptom troubleshooting.
i-SHIFT position indicator does not come on	1. 2.	Do the gauge control module troubleshooting. Substitute a known-good TCM, then recheck. If it is OK, replace the original TCM; L13Z1 engine model, R18A2 engine model.
i-SHIFT position indicator does not change or a gear position does not match	1. 2.	Do the gauge control module troubleshooting. Move the shift lever to all position, then check the SHIFT VALID N or D or A/M or + or − or R FROM SHIFTER in the DATA LIST with the HDS. If it is NG, replace the gear shift control module.
Steering wheel upshift switch does not gear change	1. 2. 3.	Steering wheel upshift switch circuit troubleshooting. Steering wheel upshift switch test. Substitute a known-good TCM, then recheck. If it is OK, replace the original TCM; L13Z1 engine model, R18A2 engine model.
Steering wheel downshift switch does not gear change	1. 2. 3.	Steering wheel downshift switch circuit troubleshooting. Steering wheel downshift switch test. Substitute a known-good TCM, then recheck. If it is OK, replace the original TCM; L13Z1 engine model, R18A2 engine model.
Does not become S-mode or can not cancel S-mode	1. 2.	Check for PGM-FI system DTC. Symptom troubleshooting.
Manual mode does not gear change of gear shift control module	Move the shift lever to all positions then check the SHIFT VALID N or D or A/M or + or − or R FROM SHIFTER in the DATA LIST with the HDS. If it is NG, replace the gear shift control module.
Engine does not crank	Symptom troubleshooting.
No transmission power to wheels	Symptom troubleshooting.
Non-creep	Symptom troubleshooting.
Engine stalls when stopping	Symptom troubleshooting.
All segments of the gear position indicator turn on. (When starting the engine, N is not indicated on the gear position indicator although the shift lever is at N position)	1. 2. 3.	Make sure the shift lever is at N position, press the brake pedal and keep it pressed. Turn the ignition switch to ON (II). Keep the brake pedal pressed until the gear position indicator indicates N. If the gear position indicator does not change to N, inspect the battery.