1991 LEXUS SC400 check engine

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Page 1357 of 4087

LEXUS SC400 1991  Service Repair Manual 
INSPECTION OF EGR SYSTEM (USA
Spec.)
INSPECT SYSTEM OPERATION
(a)  Using SST, connect terminals TE1 and E1 of the check(ºDIAGNOSISº) connector.
SST 09843±18020
(b)  Keep the engine at 3,500 rpm.
(

Page 1358 of 4087

LEXUS SC400 1991  Service Repair Manual 
INSPECTION OF EGR SYSTEM
(Exc. USA Spec.)
1. CHECK AND CLEAN FILTERS IN EGR VACUUMMODULATOR
(a)  Remove the cap and filter.
(b)  Check the filter for contamination or damage.
(c)  Using compressed ai

Page 1360 of 4087

LEXUS SC400 1991  Service Repair Manual 
(b)  Apply battery voltage across the terminals.
(c)  Check that the air flows from port E to the filter.
If operation is not as specified, replace the VSV.
4. REINSTALL VSV (a)  Install the VSV with

Page 1362 of 4087

LEXUS SC400 1991  Service Repair Manual 
INSPECTION OF EGR VALVE 
(USA Spec.)
1.  DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turn

Page 1365 of 4087

LEXUS SC400 1991  Service Repair Manual 
3.  INSPECT EGR VALVECheck for sticking and heavy carbon deposits.
If a problem is found, replace the EGR valve assembly.
4.  REINSTALL EGR VALVE (a)  Place a new gasket on the EGR valve adaptor.
NOT

Page 1385 of 4087

LEXUS SC400 1991  Service Repair Manual 
TUNE±UP
EG10Z±05
ENGINE COOLANT INSPECTION
1. CHECK ENGINE COOLANT LEVEL AT RESERVOIR TANK
The coolant level should be above the ªCOLD LEVELº at nor-
mal temperature (20 5C (68 5F)).
If low, chec

Page 1386 of 4087

LEXUS SC400 1991  Service Repair Manual 
EG0B4±0K
ENGINE OIL INSPECTION
1.  CHECK OIL QUALITYCheck the oil for deterioration, entry of water, discoloring or
thinning.
If oil quality is visibly poor, replace the oil.
Oil grade:
API grade SG

Page 1387 of 4087

LEXUS SC400 1991  Service Repair Manual 
wIf the vehicle has been running, wait 5 minutes or more
after the vehicle stops before measuring the battery
voltage.
If the voltage is less than specification, charge the battery.
HINT: Check the i