TEST OPTIONS
REASON FOR QUESTION
KNOWN INFO
18.
POSSIBLE PROBLEMS
Do backup lights operate
with new WTEC III relay
K25 installed?
WTEC III Relay K25
Replacement Test
If backup lights operate
with new WTEC III relay
K25 installed, WTEC III
relay K25 is faulty. If
backup lights do not
operate with new WTEC III
relay K25 installed,
WTEC III transmission ECU
is faulty.
e53. BACKUP LIGHT DOES NOT ILLUMINATE (CONT)
Circuit breaker CB70 OK.
Circuit breaker CB73 OK.
Both turn signals illuminate.
Engine starts.
Transmission reverse (R)
range OK.
Backup light lamps OK.
Backup light assembly OK.
WTEC III transmission controls.
WTEC III dashboard cable
assembly OK.
Rear lights cable assembly OK.
Replace WTEC III relay
K25 (para 7-9).
YES
Replace WTEC III
transmission ECU
(para 8-7).
NO
TM 9-2320-365-20-1
2-672 Change 1
Faulty WTEC III relay K25.
Faulty WTEC III
transmission ECU.
