With Scan Tool
ON-BOARD DIAGNOSTIC CHECKING
On-board diagnostic checking is performed when there has been an automatic cancellation, without cancel switch operation.
NOTE: Even when the ignition key is placed in the OFF position, all diagnostic trouble codes are stored and retained, until the battery cable is disconnected, to make sure that the problems encountered in the past can be checked.
WHEN USING THE SCAN TOOL [MULTI-USE TESTER (MUT)
(1) Connect the scan tool to the data-link connector to read out the diagnostic trouble codes.
When connecting the scan tool to a vehicle up to 1993 models, use the adapter harness supplied together.
Caution: Turn off the ignition switch beforehand whenever the scan tool is connected or disconnected.
(2) Refer to the diagnostic chart and repair the defective point.
(3) Clear the diagnostic trouble codes by the following procedure.
1) Place the ignition switch in the ON position.
2) With the SET switch in the ON state, set the main switch to ON. In less than 1.0 second thereafter, set the RESUME switch to ON.
3) With the SET switch in the ON state again, keep the stop light switch in the ON state for more than 5 seconds.
4) Temporarily place the main switch in the OFF position to let the control unit escape from the input check mode. Then place the main switch in the ON position again.
5) Check the diagnostic trouble code to verify that a normal code is output.
INPUT CHECKING
Input checks should be made when the cruise control system cannot be set and when it is necessary to check (when a malfunction related to the cruise control system occurs) whether or not the input signals are normal.
NOTE:
1. If inspection of on-board diagnostic is necessary, confirm diagnostic trouble code first and conduct input check.
2. Input check can be conducted by set operations. On-board diagnostic terminal outputs display patterns.
3. Display codes are displayed only if the circuit is normal according to the conditions shown in the trouble code descriptions (Input Check Table).
Perform checks using the following procedures.
(1) Connect a scan tool or a voltmeter to the data link connector.
NOTE: Connect a voltmeter using the same procedure as for inspection of diagnostic output.
(2) Calling up a code
1) Set the ignition switch to ON.
2) With the SET switch in the ON state, set the main switch to ON. In less than 1.0 second thereafter, set the RESUME switch to ON. Then the input check results can be displayed.
(3) Reading a code
1) Perform the individual input operations according to the input check table and read the codes.
NOTE:
1. When two or more input operations are performed simultaneously, all the associated code numbers are output in ascending order.
2. If no code is output by performing any of input operations, the control unit power supply circuit or SET and RESUME switches are probably defective.
Check the check tables 1 and 2.
2) Set main switch to OFF.