Ford Ranger EV (2001 year). Manual — part 76

412-02-9

412-02-9

Heating and Ventilation

DIAGNOSIS AND TESTING (Continued)

PINPOINT TEST B: DTC B1249 BLEND DOOR FAILURE

TEST STEP

ACTION TO TAKE

B3 CHECK CIRCUITS 245 (BR/LG), 246 (P), 436 (R/LG), 437 (Y/LG),

AND 438 (R/W) FOR OPEN(S)

•

Connect 104-Pin Breakout Box (BOB) to IAA module C1945; leave the

Yes =

GO to B4.

IAA module disconnected.

•

With key OFF, measure the resistance of the BR/LG wire between pin 7

No =

REPAIR the wire(s) in

on blend door actuator C240 and BOB pin 6.

question.

•

With key OFF, measure the resistance of the P wire between pin 8 on

blend door actuator C240 and BOB pin 7.

•

With key OFF, measure the resistance of the R/LG wire between pin 6

on blend door actuator C240 and BOB pin 85.

•

With key OFF, measure the resistance of the Y/LG wire between pin 1

on blend door actuator C240 and BOB pin 51.

•

With key OFF, measure the resistance of the R/W wire between pin 5 on

blend door actuator C240 and BOB pin 72.

•

Are the resistances less than 5 ohms?

B4 CHECK CIRCUITS 245 (BR/LG), 246 (P), 436 (R/LG), AND 437

(Y/LG) FOR SHORT(S) TO GROUND

•

With key OFF, measure the resistance between BOB pins 6, 7, 51, 85

Yes =

GO to B5.

and ground (BOB pin 80).

•

Are the resistances greater than 10,000 ohms?

No =

REPAIR the wire(s) in

question.

B5 CHECK RESISTANCE OF BLEND DOOR ACTUATOR

•

With key OFF, reconnect blend door actuator C240.

Yes =

REPLACE the IAA module.

•

With key OFF, connect the IAA module to BOB; leave BOB connected

REFER to

Section 412-04

.

to IAA module C1945.

NOTE: You must set the temperature control knob to the full warm

position before disconnecting the IAA module from the BOB. Failure to do

so will result in misdiagnosis of the blend door actuator.

•

With key ON, set the mode select knob to the PANEL/FLOOR position

and the temperature control knob to the full warm position, and monitor

the IAA module PID BLENDDR until it indicates approximately 90%.

•

With key OFF, disconnect the IAA module from BOB; leave BOB

connected to IAA module C1945.

•

With key OFF, measure the resistance between the indicated BOB pins

and verify the resistances below:

— BOB pins 51 and 85 = 250-1,500 ohms
— BOB pins 51 and 72 = 3,500-6,000 ohms
— BOB pins 72 and 85 = 5,000-7,000 ohms

•

Are the resistances OK?

No =

REPLACE the blend door

actuator.

PINPOINT TEST C: DTC B1250 AIR TEMPERATURE INTERNAL SENSOR CIRCUIT FAILURE

TEST STEP

ACTION TO TAKE

C1 CHECK IN-CAR TEMPERATURE SENSOR

•

Connect 104-Pin Breakout Box (BOB) to IAA module C1945; leave IAA Yes =

REPLACE the IAA module.

module disconnected.

REFER to

Section 412-04

.

•

With key OFF, measure the resistance between BOB pins 49 and 79 and

compare the reading to the values below:

No =

GO to C2.

Actual Temperature (Approximate)
— 0

°

C (32

°

F) = 91,000-100,700 ohms

(Continued)

412-02-10

412-02-10

Heating and Ventilation

DIAGNOSIS AND TESTING (Continued)

PINPOINT TEST C: DTC B1250 AIR TEMPERATURE INTERNAL SENSOR CIRCUIT FAILURE

TEST STEP

ACTION TO TAKE

— 5

°

C (41

°

F) = 71,100-78,700 ohms

— 10

°

C (50

°

F) = 56,000-62,000 ohms

— 15

°

C (59

°

F) = 44,400-49,100 ohms

— 20

°

C (68

°

F) = 35,500-39,200 ohms

— 25

°

C (77

°

F) = 28,500-31,500 ohms

— 30

°

C (86

°

F) = 23,000-25,500 ohms

— 35

°

C (95

°

F) = 18,700-20,700 ohms

— 40

°

C (104

°

F) = 15,300-16,900 ohms

•

Is the resistance OK?

C2 CHECK CIRCUITS 3050 (W/O) AND 3060 (GY/R) FOR OPEN(S)

•

With key OFF, disconnect in-car temperature sensor C2997 and measure

Yes =

GO to C3.

the resistance of the W/O wire between in-car temperature sensor C2997

and BOB pin 49.

•

With key OFF, measure the resistance of the GY/R wire between in-car

No =

REPAIR the wire(s) in

temperature sensor C2997 and BOB pin 79.

question.

•

Are the resistances less than 5 ohms?

C3 CHECK CIRCUIT 3050 (W/O) FOR SHORT TO GROUND

•

With key OFF, measure the resistance between BOB pin 49 and ground

Yes =

GO to C4.

(BOB pin 80).

•

Is the resistance greater than 10,000 ohms?

No =

REPAIR the W/O wire.

C4 CHECK CIRCUIT 3050 (W/O) FOR SHORT TO POWER

•

With key ON, measure the voltage between BOB pin 49 and ground

Yes =

REPAIR the W/O wire.

(BOB pin 80).

•

Is the voltage greater than 0 volts?

No =

GO to C5.

C5 CHECK ASPIRATOR INSTALLATION

•

With key OFF, access the in-car temperature sensor behind the glove

Yes =

REPLACE the in-car

compartment.

temperature sensor.

•

Check for proper installation of in-car temperature sensor hose and

No =

REPAIR as necessary.

elbow.

•

Is the aspirator installed correctly and the hose connected?

PINPOINT TEST D: DTC B1254 AIR TEMPERATURE EXTERNAL SENSOR CIRCUIT FAILURE

TEST STEP

ACTION TO TAKE

D1 CHECK AMBIENT TEMPERATURE SENSOR

•

With key OFF, disconnect ambient temperature sensor C1952, measure

Yes =

GO to D2.

the resistance between the terminals of the ambient temperature sensor

and compare the reading to the values below:

Actual Temperature (Approximate)

No =

REPLACE the ambient

temperature sensor.

— 0

°

C (32

°

F) = 91,000-100,700 ohms

— 5

°

C (41

°

F) = 71,100-78,700 ohms

— 10

°

C (50

°

F) = 56,000-62,000 ohms

— 15

°

C (59

°

F) = 44,400-49,100 ohms

— 20

°

C (68

°

F) = 35,500-39,200 ohms

— 25

°

C (77

°

F) = 28,500-31,500 ohms

— 30

°

C (86

°

F) = 23,000-25,500 ohms

— 35

°

C (95

°

F) = 18,700-20,700 ohms

— 40

°

C (104

°

F) = 15,300-16,900 ohms

•

Is the resistance OK?

(Continued)

412-02-11

412-02-11

Heating and Ventilation

DIAGNOSIS AND TESTING (Continued)

PINPOINT TEST D: DTC B1254 AIR TEMPERATURE EXTERNAL SENSOR CIRCUIT FAILURE

TEST STEP

ACTION TO TAKE

D2 CHECK CIRCUITS 3061 (LB/O) AND 3062 (BK/W) FOR OPEN(S)

•

Connect 104-Pin Breakout Box (BOB) to IAA module C1945; leave IAA Yes =

GO to D3.

module disconnected.

•

With key OFF, measure the resistance of the LB/O wire between ambient No =

REPAIR the wire(s) in

temperature sensor C1952 and BOB pin 96.

question.

•

With key OFF, measure the resistance of the BK/W wire between in-car

temperature sensor C1952 and BOB pin 77.

•

Are the resistances less than 5 ohms?

D3 CHECK CIRCUIT 3061 (LB/O) FOR SHORT TO GROUND

•

With key OFF, measure the resistance between BOB pin 96 and ground

Yes =

GO to D4.

(BOB pin 80).

•

Is the resistance greater than 10,000 ohms?

No =

REPAIR the LB/O wire.

D4 CHECK CIRCUIT 3061 (LB/O) FOR SHORT TO POWER

•

With key ON, measure the voltage between BOB pin 77 and ground

Yes =

REPAIR the LB/O wire.

(BOB pin 80).

•

Is the voltage greater than 0 volts?

No =

REPLACE the IAA module.

REFER to

Section 412-04

.

PINPOINT TEST E: DTC C1776 HEATER SYSTEM FAILURE

TEST STEP

ACTION TO TAKE

E1 RETRIEVE CONTINUOUS DIAGNOSTIC TROUBLE CODES

(DTCs) FROM INTERFACE ADAPTER ASSEMBLY (IAA) MODULE

WHILE IN PANEL/FLOOR MODE

•

With key ON, set the mode select knob to the PANEL/FLOOR position Yes = REFER to

Symptom Chart.

and the temperature control knob to the full warm position.

•

Wait approximately 45 seconds and retrieve continuous DTCs from the

No =

GO to E2.

IAA module.

•

Do any climate control DTCs occur along with DTC C1776 Heater

System Failure?

E2 CHECK STATUS OF POSITIVE TEMPERATURE COEFFICIENT

(PTC) HEATER CORES

NOTE: Turn the key to the OFF position and clear continuous IAA

Yes =

GO to E11.

module DTCs before proceeding. If PIDs CORE A and CORE B

indicate RETRY and PIDs HTR CAR and HTR CBR indicate YES

after 45 seconds, wait approximately 4 minutes for the results. If

CORE A or CORE B does not indicate FAULT, cycle the ignition key

OFF/ON and repeat.

•

With key ON, set the mode select knob to the PANEL/FLOOR position

and the temperature control knob to the full warm position, and monitor

IAA module PIDs CORE A, CORE B, HTR CAR, and HTR CBR

for approximately 45 seconds.

•

Do CORE A and CORE B PIDs both indicate FAULT?

No =

If only CORE A PID

indicates FAULT, GO to

E3.
If only CORE B PID

indicates FAULT, GO to

E7.

E3 CHECK PTC HEATER CORE A

•

Disconnect the 12-volt auxiliary battery negative cable.

Yes =

GO to E4.

(Continued)

412-02-12

412-02-12

Heating and Ventilation

DIAGNOSIS AND TESTING (Continued)

PINPOINT TEST E: DTC C1776 HEATER SYSTEM FAILURE

TEST STEP

ACTION TO TAKE

•

Remove the high-voltage power distribution box (HVPDB) cover.

No =

REPLACE the PTC heater

•

Disconnect PTC switching module high-voltage C1912 and measure the

core.

resistance between the DB wire and DG wire on PTC switching module

C1912M.

•

Is the resistance between 65 and 140 ohms?

E4 CHECK PTC HEATER CORE A CONTROL SIGNAL

•

With key OFF, reconnect PTC switching module C1912.

Yes =

GO to E17.

•

Reinstall HVPDB cover.

No =

GO to E5.

•

Connect 104-Pin Breakout Box (BOB) to IAA module and IAA module

C1945.

•

Reconnect the 12-volt auxiliary battery negative cable.

•

With key ON, set the mode select knob to the PANEL/FLOOR position

and the temperature control knob to the full warm position, and monitor

IAA module PID CORE A.

•

Cycle the ignition key (if necessary) OFF/ON until the CORE A PID

indicates ON.

•

Measure the voltage between BOB pin 33 and ground (BOB pin 80).

•

Is the voltage greater than 2 volts?

E5 CHECK PTC HEATER CORE A CONTROL CIRCUIT FOR

SHORT TO GROUND

•

With key OFF, disconnect BOB from IAA module; leave BOB

Yes =

GO to E6.

connected to IAA module C1945.

•

With key OFF, measure the resistance between BOB pin 33 and ground

No =

REPLACE the IAA module.

(BOB pin 80).

REFER to

Section 412-04

.

•

Is the resistance less than 7,000 ohms?

E6 CHECK CIRCUIT 3260 (O/W) FOR SHORT TO GROUND

•

Reconnect the 12-volt auxiliary battery negative cable.

Yes =

REPLACE the PTC

switching module. REFER

to

Section 412-04

.

•

With key OFF, disconnect PTC switching module C1999 and measure

No =

REPAIR the O/W wire.

the resistance between BOB pin 33 and ground (BOB pin 80).

•

Is the resistance greater than 10,000 ohms?

E7 CHECK PTC HEATER CORE B

•

Disconnect the 12-volt auxiliary battery negative cable.

Yes =

GO to E8.

•

Remove the high-voltage power distribution box (HVPDB) cover.

No =

REPLACE the PTC heater

•

Disconnect PTC switching module high-voltage C1912 and measure the

core.

resistance between the R wire and W wire on PTC switching module

C1912M.

•

Is the resistance between 65 and 140 ohms?

E8 CHECK PTC HEATER CORE B CONTROL SIGNAL

•

With key OFF, reconnect PTC switching module C1912.

Yes =

GO to E17.

•

Reinstall HVPDB cover.

No =

GO to E9.

•

Connect 104-Pin Breakout Box (BOB) to IAA module and IAA module

C1945.

•

Reconnect the 12-volt auxiliary battery negative cable.

•

With key ON, set the mode select knob to the PANEL/FLOOR position

and the temperature control knob to the full warm position, and monitor

IAA module PID CORE B.

•

Cycle the ignition key (if necessary) OFF/ON until the CORE B PID

indicates ON.

•

Measure the voltage between BOB pin 34 and ground (BOB pin 80).

•

Is the voltage greater than 2 volts?

(Continued)