Problem Symptoms Table

This system uses the multiplex communication system, so check diagnosis system of the multiplex communication system before you proceed with troubleshooting.

The table below will be useful for you in troubleshooting these electrical systems. The most likely causes of the malfunction are shown in the order of their probability. Inspect each part in the order shown, and replace the part when it is found to be faulty.

If the instruction "Proceed to next circuit inspection shown on the chart" is given in the flow chart for each circuit, proceed to the circuit with the next highest number in the table to continue the check.
If the problem still occurs even though there are no abnormalities in any of the other circuits, then check and replace multiplex tilt & telescopic ECU.

PROBLEM SYMPTOMS

Symptom	Suspect Area	See
Both tilt and telescopic: Manual, auto away/return and memory functions Do not operate Stop part way Do not stop	Multiplex communication system ECU power source circuit Unlock warning switch circuit Tilt motor circuit Telescopic motor circuit Actuator power source circuit	PRE-CHECK DTC B2620 ECU POWER SOURCE CIRCUIT MALFUNCTION CIRCUIT DESCRIPTION CIRCUIT DESCRIPTION CIRCUIT DESCRIPTION CIRCUIT DESCRIPTION
Tilt only: Manual, auto away/return and memory functions Do not operate Stop part way Do not stop	Multiplex communication system Tilt motor circuit	PRE-CHECK CIRCUIT DESCRIPTION
Telescopic only: Manual, auto away/return and memory functions Do not operate Stop part way Do not stop	Multiplex communication system Telescopic motor circuit	PRE-CHECK CIRCUIT DESCRIPTION
Both tilt and telescopic: Only tilt and telescopic manual switch function does not operate	Multiplex communication system Tilt and telescopic manual switch circuit	PRE-CHECK CIRCUIT DESCRIPTION
Tilt only: Only tilt and telescopic manual switch function does not operate	Multiplex communication system Tilt and telescopic manual switch circuit	PRE-CHECK CIRCUIT DESCRIPTION
Telescopic only: Only tilt and telescopic manual switch function does not operate	Multiplex communication system Tilt and telescopic manual switch circuit	PRE-CHECK CIRCUIT DESCRIPTION
Both away and return: Only auto away/return function does not operate	Check status of auto away function using LEXUS handheld tester Multiplex communication system Ignition switch Unlock warning switch	- PRE-CHECK IGNITION CIRCUIT DESCRIPTION
Only away: Only auto away/return function does not operate	Multiplex communication system Unlock warning switch Ignition switch	PRE-CHECK CIRCUIT DESCRIPTION IGNITION
Only return: Only auto away/return function does not operate	Multiplex communication system Unlock warning switch Ignition switch	PRE-CHECK CIRCUIT DESCRIPTION IGNITION
Only memory function does not operate	Multiplex communication system	PRE-CHECK