Symptom:
FAN S TAGE 1 RELAY CON TROL S HORTED
POSSIBLE CAUSES
FAN STAGE 1 RE LAY
FAN STAGE 1 RE LAY HIGH SIDE CON TROL CIRCUIT SH ORTE D TO GROUND
FAN STAGE 1 RE LAY HIGH SIDE CON TROL CIRCUIT SH ORTE D TO GROUND CIRCUIT
CABIN H EATE R CONTROL UN IT
TE S T ACTION AP PLICAB ILITY
1 WA R N I N G : N E V E R O P E R AT E T H E H E AT E R I N A N E N C L O S E D A R E A
TH AT D OES N OT HAVE EXH AU S T VEN TILATION FACILITIES . A LWAYS
VEN T THE EXHAU S T WHE N OP ERATIN G THE HE ATER. F AILU R E TO
FOLLOW TH ES E IN S TRU CTIONS CAN RES U LT IN P E RS ON AL IN J U RY
OR D E ATH .
CAU TION : D O N OT P E R F ORM TH IS TE S T U N LES S D IRE CTE D H ER E B Y
TH E HEATER P RE -TES T. ALWAYS P ERF ORM THE HEATER P RE-TES T
P RIOR TO P ERF ORMING AN Y OTHER TES T F OR TH E R ES U LT TO BE
VAL I D .
Tur n th e ign it ion off.
In st all a su bst it u t e r ela y in pla ce of t h e Fa n St a ge 1 Rela y.
Tur n th e ign it ion on .
Ver ify t h a t th e Ca bin H ea t er i s swit ch ed off.
Set t h e blen d con t r ol t o th e m a x h ea t posit ion a n d t he m ode cont r ol t o th e floor
posit ion .
Wit h th e DRBIII", er a se t he Ca bin Hea t er Modu le’s DTCs.
St a r t th e engin e. Allow th e en gin e t o idle.
Wit h t h e DRBIII, m on it or for Ca bin H ea t er Modu le DTCs wh ile per for m ing t h e
followin g st ep.
NOTE: Do not disconnect the vehicle’s battery or the heater’s main power
su p p ly w hi le th e h e at e r is i n o p e ra tio n or i n ru n -d o w n m o d e . Fa i lu re to
fo ll o w t h e s e i n s t ru c t i o n s c a n r e s u l t i n e x c es s e mi s s io ns fr o m t h e hea t e r
during heater operation.
Swit ch th e Ca bin H eat er on. If n ecessa r y, allow t h e h ea t er t o ru n th r ou gh a t lea st on e
cycle of oper a t ion (a ppr oxim a t ely 10 min u t es), a nd t h en swit ch th e hea t er off.
Tur n th e en gin e off.
Does t h e DRBIII" displa y: FAN STAGE 1 RE LAY CON TROL SH ORTE D?
All
Ye s → Go To 2
No → Repla ce th e or igin a l F a n St a ge 1 Rela y in a ccor da n ce wit h t h e
Ser vice In for m a t ion .
Per for m H E ATE R VERIF ICATION TE ST - VER 1.
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CABI N H EAT ER