Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Preliminary Inspection

Preliminary Inspection

a. Know and understand the customer's concern.
b. Verify the concern by operating the vehicle.
c. Check the fluid level and condition.
d. Check for non-factory add-on items.
e. Check shift linkages for proper adjustment.
f. Check TSBs and OASIS messages for the concern.

Diagnostics






- Perform On-Board Diagnostic Procedures, key on engine off (KOEO), key on engine running (KOER).

- Record all diagnostic trouble codes (DTCs).

- Repair all non-transmission codes first.

- Repair all transmission codes second.

- Erase all continuous codes and attempt to repeat them.

- Repair all continuous codes.

- If only pass codes, proceed to Diagnosis by Symptom charts for further information and diagnosis.

By following the diagnostic sequence the service technician will be able to diagnose and repair the concern the first time.