Toyota Land Cruiser 1988 Repair Manual page 154

EFI SYSTEM- Diagnosis System Fl-23
CANCELLING DIAGNOSTIC CODE
1. After repair of trouble area, the diagnostic code retained
in memory by the ECU must be cancelled out by remov-
ing the EFI fuse (15A) for 30 seconds or more, depend-
ing on ambient temperature (the lower the temperature,
the longer the fuse must be left out) with the ignition
switch OFF.
NOTE:
• Cancellation can also be done by removing the battery
negative (-) terminal, but in this case, other memory
systems (clock, etc.) will also be cancelled out.
• If the diagnostic code is not cancelled out, it will be
retained by the ECU and appear along with a new code
in the event of future trouble.
• If it is necessary to work on engine components requir-
ing removal of the battery terminal, a check must first
be made to see if a diagnostic code has been recorded.
2. After cancellation, road test the vehicle to check that a
"normal" code is now read on the "CHECK" engine
warning light.
If the same diagnostic code appears, it indicates that the
trouble area has not been repaired thoroughly.
DIAGNOSIS INDICATION
1. Including "normal", the ECU is programmed with the
following 18 (ex. California vehicles) or 19 (California
vehicles)· diagnostic codes.
2. When 2 or more codes are indicated, the lowest number
(code) will appear first.
However, no other code will appear along with code
No.11.
3. All detected diagnostic codes, except code No.51, will
be retained in memory by the ECU from the time of detec-
tion until cancelled out.
4. Once the malfunction is cleared, the "CHECK" engine
warning light on the instrument panel will go out but the
diagnostic code(s) remain stored in ECU memory (ex-
cept for code No.51 ) .