Honda Prelude 1993 Service Manual page 143

Troubleshooting Flowchart - VTEC Solenoid Valve
VTEC
-f6il
lttll Maffunction Indicato. Lamp (MlL) indicates Cliagnostic Trouble Code (DTC) 21:A problem in the \rrEC
Solenoid Valve circNJit,
*Road Test:
Accelerate in 2nd gear to an ongine spged over 6000 rpm.
Hold that engine sp€ed for at least two seconds.
Ropeat this test at least threo times.
-r-'
\ ---.1- /
116l -l 21 l-
----i-
-
-
MIL hr! b€on ,aoon6d on.
-
With s€rvlc€ chock connoctor
Fmpod lp.go 1 1 -42), cod6 2 1
i8 indhatod.
Do tho onglno c-ontrol modole
(ECMI Rosot Plocoduro (p.go
1 1 - 4 3 ) .
Wann up ongino to normd op€rat-
ing tompo.ature lradiator t6n
como! onr.
Do thg Road Test.r
Intorrnlttaot lailuro, 3y8tom ir OK
at thi! tim6.
Ch6ck tor poo. connoctiona o.
10036 wiro. at VTEC aolonoid
valve and ECM,
ls MIL on and does it indicate
code 21?
Dbconnoc-t tho 1 P connoctd from
tho VTEC aolonold vdv6.
Ch6d( lor cootinuitv betwoon lP
connoctoa torminal and body
ls there 14-300?
lTo page 6-761
(cont'd)