If a DTC was displayed in the initial DTC check, the problem may have occurred in a wire harness
or connector in that circuit in the past. Check the wire harness and connectors.
B: SYSTEM NORMAL
A: TROUBLESHOOTING OF EACH PROBLEM SYMPTOM
The problem is still occurring in a place other than the diagnostic circuit (the DTC displayed first is
either for a past problem or a secondary problem).
4. SYMPTOM SIMULATION
HINT:
The most difficult case in troubleshooting is when no problem symptoms occur. In such a case, a
thorough problem analysis must be carried out. A simulation of the same or similar conditions and
environment in which the problem occurred in the customer's vehicle should be carried out. No matter
how much skill or experience a technician has, troubleshooting without confirming the problem
symptoms will lead to important repairs being overlooked and mistakes or delays.
For example:
With a problem that only occurs when the engine is cold or as a result of vibration caused by the road
during driving, the problem can never be determined if the symptoms are being checked on a stationary
vehicle or on a vehicle with a warmed-up engine. Vibration, heat or water penetration (moisture) is
difficult to reproduce. The symptom simulation tests below are effective substitutes for the conditions and
can be applied on a stationary vehicle.
Important points in the symptom simulation test:
In the symptom simulation test, the problem symptoms as well as the problem area or parts must
be confirmed. First, narrow down the possible problem circuits according to the symptoms. Then,
connect the tester and carry out the symptom simulation test, judging whether the circuit being
tested is defective or normal. Also, confirm the problem symptoms at the same time. Refer to the
problem symptoms table for each system to narrow down the possible causes.
a. VIBRATION METHOD:
When a malfunction seems to occur as a result of vibration.
1. PART AND SENSOR
Apply slight vibration with a finger to the part of the sensor suspected to be the cause of the
problem, and check whether or not the malfunction occurs.
NOTE:
Applying strong vibration to relays may open them.
2009 Toyota Tundra
2009 GENERAL INFORMATION Introduction - Tundra