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Ford Falcon. Manual - part 325

412-04-13 Control

Components 412-04-13

DIAGNOSIS AND TESTING (Continued)

Pin Number(s)

Circuit Designation/Description

Normal Condition/Measurement

Circuit 682 (R)

Resistance (Ohm) between pins 1 and 3

Sensor GND

2.7K ~ 3.3K ohms

Circuit 915P (P-L)

Note 1

CAN bus to ICC

Circuit 915J (P-L)

Note 1

CAN bus to PCM

Circuit 1133 (BR)

Voltage ( V ) to vehicle body electrical ground

Blower Motor

Approximately + Battery ( 12 ~ 14v) while engine

running, blower connected and HIM

disconnected.

Circuit 57CB (B)

Resistance (Ohm) to vehicle body electrical

Power GND

ground

0 ohms approx.

CAUTION: Do not probe terminals with any

type of meter as damage to vehicle systems may

result.

CAUTION: Do not insert probes in to front of

terminal, damage may result. Probe only rear (wire

entry) of connectors.

Dual Zone Actuator Terminal Connections 5 way
NOTE: View from wire entry side (rear).

Pin Number(s)

Circuit Designation/Description

Normal Condition/Measurement

Potentiometer +

Resistance (Ohm) between pins 1 and 3

2.7K ~ 3.3K ohms

Potentiometer

Resistance (Ohm) between pins 2 and 3

Wiper

0 ~ 3.3K ohms (value dependant on motor output

coupling angle)

Potentiometer -

Resistance (Ohm) between pins 1 and 3

2.7K ~ 3.3K ohms

Motor Connection

Diode (D) Continuity between pins 4 and 5

0.5 ~ 0.7V

Motor Connection

Diode (D) Continuity between pins 4 and 5

0.5 ~ 0.7V

HIM Input Connection D (Evaporator Temperature Sensor 2 Way)
NOTE: View from wire entry side (rear).

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412-04-14 Control

Components 412-04-14

DIAGNOSIS AND TESTING (Continued)

Pin Number(s)

Circuit Designation/Description

Normal Condition/Measurement

Sensor ground

Voltage ( V ) between HIM terminal connection D

pin 1 and C376 pin 13.

0V (ground)

Sensor Supply

Voltage ( V ) between HIM terminal connection D

pin 2 and C376 pin 13
NOTE: With Ignition ON and sensor

disconnected, refer to sensor voltage from

sensor output table B, Pinpoint test B.

fan circuit is protected with a 40 amp fuse (F5,

Air Conditioning & HVAC Relay and

F6-both green) also located in this fuse box.

Fuses

The three relay coils are protected by a single 15A

The air conditioning compressor cut-out relay (WAC

fuse (F2-blue) located in the instrument panel fuse

relay, R3-black) is located in the Engine Compartment box.

Fuse Box.

The HIM electrical circuits are protected with two

The A/C compressor clutch is protected with a 30 amp fuses, one 15 amp (F4-blue) and one 10 amp,

fuse (F11-pink, combined with the engine fuse)

(F27-red), both located in the Instrument Panel Fuse

located in the Engine Compartment Fuse Box.

Box.

The A/C condenser fans (engine cooling fans) are

The HVAC blower fan circuit is protected with a 40

controlled with three relays (R8, R9, R10-all white)

amp fuse (F7-green) located in the Engine

located in the Engine Compartment Fuse Box. Each

Compartment Fuse Box.

Pinpoint Tests

PINPOINT TEST A : TEMPERATURE SENSOR — AMBIENT (ACC)

NOTE: REFER to Section 412-02 SYMPTOM CHART BEFORE PROCEEDING

Test Step

Result / Action to Take

WIRING INSPECTION - SHORT TO VEHICLE BODY

Start and run engine until normal operating temperature is reached.

Yes

Go to A2 if code B1257 is set.

Ensure vehicle battery voltage is within normal operating range

Go to A3 if code B1255 is set.

(12~14volts) before proceeding with test.

Using WDS scan tool, record all DTC’s set in the HIM memory.

System OK

Using WDS scan tool, clear all DTC’s set in the HIM memory.

Using WDS scan tool, perform HVAC On Demand Self Test.

Are any DTC codes set?

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412-04-15 Control

Components 412-04-15

DIAGNOSIS AND TESTING (Continued)

Test Step

Result / Action to Take

VEHICLE WIRING INSPECTION - SHORT TO VEHICLE

BODY

Disconnect the 12 way connector C-376 from the HIM. Using a

Yes

resistance meter, attach the negative probe to a good metal body

Go to A4

earth connection and check the vehicle wiring continuity from HIM

connector lead 682 Red wire and lead 234 white-Blue wire for short

Repair wiring short to vehicle body.

circuit to vehicle body.

Does the meter read infinite resistance to the vehicle metal body
for both leads?

VEHICLE WIRING INSPECTION - CONTINUITY

With the 12way connector C-376 removed from the HIM and the 2

Yes

way connector removed from the Ambient sensor C-377, use a

Go to A4

resistance meter and check the vehicle wiring continuity lead 682 Red

wire and lead 234 White-Blue wire from HIM connector to sensor

Repair wiring fault.

connector.

Does the meter read 0 ohms end to end for each lead?

MODULE FUNCTION CHECK - AMBIENT SENSOR

TEMPERATURE

Reconnect the 12way connector C-376 to the HIM and the 2way

Yes

connector C-377 to the Ambient sensor.

System OK

Using the WDS Scan Tool, read the EXT_TEMP value (Ambient

sensor temperature) from the HIM.

Go to A5

Compare the value against a temperature probe located near the
Ambient sensor.

NOTE:

Accurate operation of the sensor relies on air moving

across the sensor. Therefore, while the vehicle is stationary or at
low speed or operating for a short period of time only, the
display may differ slightly from the true ambient temperature.

Do the temperatures closely match?

SENSOR INSPECTION - RESISTANCE

CHARACTERISTIC

Disconnect the 12way connector C-376 from the HIM. Using a

Yes

resistance meter, attach probes across lead 682 Red wire and lead

Go to A6

234 White-Blue wire and compare the reading using Table A and a

temperature thermometer located near the sensor.

Replace Ambient sensor

Is the resistance reading within specification (+/- 5 degC)?

MODULE FUNCTION CHECK - AMBIENT SENSOR

SUPPLY VOLTAGE

Reconnect the 12way connector C-376 to the HIM and the 2way

Yes

connector C-377 to the Ambient sensor.

System OK.

Using a volt meter, attach the positive probe into rear of connector

C-376 lead 682 Red wire and negative probe to lead 234 White-Blue

Replace HIM.

wire.

Ensure Ignition key is ON and HIM responds to ICC controls.

Using table A, compare the Ambient sensor voltage reading against a
temperature probe located next to the Ambient sensor.

Does the voltage value closely match the temperature (+/- 5
degC)?

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412-04-16 Control

Components 412-04-16

DIAGNOSIS AND TESTING (Continued)

Temperature

Sensor

Sensor Voltage

Table A

Degrees

Resistance

(Volts)

NOTE: Use this table as a guide only. Minor

(Celsius)

(Ohms)

variations between actual readings are acceptable.

3.7k

2.97

Temperature

Sensor

Sensor Voltage

3.1k

2.74

Degrees

Resistance

(Volts)

2.5k

2.51

(Celsius)

(Ohms)

2.1k

2.28

-30

13.3k

4.20

1.8k

2.05

-25

12.2k

4.14

1.5k

1.83

-20

11.1k

4.06

1.2k

1.62

-15

9.8k

3.97

1.0k

1.43

-10

8.6k

3.86

0.8k

1.28

-5

7.4k

3.72

NOTE: The Ambient sensor is an integral part of the

6.3k

3.56

Left Hand Side external rear view mirror assembly.

5.3k

3.38

Refer to section 501-19 for mirror assembly

4.5k

3.18

replacement instructions.

PINPOINT TEST B : TEMPERATURE SENSOR — EVAPORATOR (ACC/MCC)

NOTE: REFER to Section 412-02 SYMPTOM CHART BEFORE PROCEEDING

Test Step

Result / Action to Take

SYSTEM ON DEMAND SELF TEST

Start and run engine until normal operating temperature is reached.

Yes

Go to B2 if code B2014 is set.

Ensure vehicle battery voltage is within normal operating range

Go to B3 if code B1947 is set.

(12~14volts) before proceeding with test.

Using WDS scan tool, record all DTC’s set in the HIM memory.

System OK

Using WDS scan tool, clear all DTC’s set in the HIM memory.

Using WDS scan tool, perform HVAC On Demand Self Test.

Are any DTC codes set?

SENSOR WIRING INSPECTION

Disconnect the 2 way Evaporator sensor connector D from the HIM

Yes

and inspect terminals on the sensor lead assembly for damage or

Replace Evaporator sensor

corrosion.

Do the terminals appear damaged?

Go to B3

SENSOR INSPECTION - RESISTANCE

CHARACTERISTIC

Turn off the Air Conditioner, select face outlet, full cold (not A/C Max),

Yes

(‘C’ or ‘Low’ for ACC) and operate HVAC blower at full speed to

Go to B4

stabilise the Evaporator sensor temperature.

Disconnect the 2 way Evaporator sensor connector D from the HIM.

Replace Evaporator sensor

Carefully insert the test probes of a resistance meter in to the REAR
of the Evaporator sensor connector (wire side). Inserting probes in to
front of terminals will damage the sensor assembly and cause
intermittent A/C operation. Compare the sensor resistance value from
Table B with a temperature thermometer located in the face outlet.

Is the resistance reading within specification (+/- 5 degC) as per
table B?

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