Ford 2003 Mustang Workshop Manual page 3472

The individual reversing lamp
is inoperative
The reversing lamps are on
continuously
Pinpoint Tests
PINPOINT TEST R: THE REVERSING LAMPS ARE INOPERATIVE
R1 CHECK THE VOLTAGE TO THE DTR SENSOR (A/T) OR
THE REVERSING LAMP SWITCH (M/T)
Key in OFF position.
Disconnect: DTR Sensor C167 (A/T).
Disconnect: Reversing Lamp Switch C169 (M/T).
Key in ON position.
If equipped with A/T, measure the voltage between DTR
sensor C167 Pin 9, Circuit 1087 (OG), harness side and
ground.
If equipped with M/T, measure the voltage between
reversing lamp switch C169, Circuit 1087 (OG), harness
side and ground.
Is the voltage greater than 10 volts?
R2 CHECK CIRCUIT 140 (BK/PK) FOR OPEN
Key in OFF position.
If equipped with A/T, measure the resistance between
DTR sensor C167 Pin 11, Circuit 140 (BK/PK), harness
side and ground.
Bulb.
Circuitry.
Circuitry.
DTR sensor (A/T).
Reversing lamp
switch (M/T).
Test Step
GO to Pinpoint
Test S .
GO to Pinpoint
Test T .
Result / Action to Take
Yes
GO to R2 .
No
REPAIR the circuit. TEST the
system for normal operation.
Yes
INSTALL a new DTR sensor
(A/T) or reversing lamp switch
(M/T); REFER to Section 307-
01 , Section 308-03A or
Section 308-03B . TEST the