Toyota Corolla (E120) 2002–2008 Repair Manual / Introduction / How to troubleshoot ecu controlled
systems / Customer problem analysis
Toyota Corolla (E120): Customer problem analysis
Hint
:
- in troubleshooting, the problem symptoms must be confirmed accurately, meaning that all preconceptions must be set aside in order to make an accurate judgement. To ascertain what the problem symptoms are, it is extremely important to ask the customer about the problem and conditions when it occurred.
- The following 5 items are important points in the problem analysis. Past problems which are thought to be unrelated and the repair history, etc. May also help in some cases. Therefore, as much information as possible should be gathered and its relationship with the problem symptoms should be correctly ascertained for use as reference in troubleshooting. A customer problem analysis table is provided for your use in the diagnostics section for each system.

(Sample) supplemental restraint system check sheet.

Other materials:
Definition of terms
Term
Definition
Monitor description
Description of what the ecm monitors and how it detects malfunctions
(monitoring purpose and its details).
Related dtcs
Diagnostic code
Typical enabling condition
Preconditions that allow the ecm to detect ...
Warning lights
Warning lights inform the driver of malfunctions in the indicated vehicle’s systems.
*1: Vehicles without a smart key system:
These lights turn on when the engine switch is turned to the “ON” position to indicate
that a system check is being performed. They will turn off after the engi ...
Check open circuit
For the open circuit in the wire harness in fig. 1, Perform
a resistance check in step (b) or a voltage check in step
(c) to locate the section.
Check the resistance.
Disconnect connectors a and c and measure the
resistance between them.
Resistance: 1 Ω or les ...


