Pinpoint Test I: Incorrect/Erratic Direction of Airflow From Outlet(s)

Climate Control System

Pinpoint Tests

Pinpoint Test I: Incorrect/Erratic Direction of Airflow From Outlet(s)

Refer to Wiring Diagram Set 54, Manual Climate Control System for schematic and connector information. Diagrams By Number

Refer to Wiring Diagram Set 55, Automatic Climate Control System for schematic and connector information. Diagrams By Number

Normal Operation

Under normal operation, to rotate the mode door actuator, the HVAC module supplies voltage to the defrost/panel/floor mode door actuator motor through the circuit CH229 (WH/BU), and supplies ground through circuit CH228 (YE/GY). To reverse the mode door actuator rotation, the HVAC module reverses the voltage and ground circuits.

The mode door actuator feedback resistor is supplied a ground from the HVAC module through circuit RH111 (GY/BU) and a 5-volt reference voltage on circuit LH111 (BN/WH). The HVAC module reads the voltage on the mode door actuator feedback circuit VH436 (YE/VT) to determine the mode door actuator position, by the position of the actuator feedback resistor wiper arm.

- DTC B1003 Mode Door Failure - The module senses no change in actuator feedback voltage when the actuator motor has been energized.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Defrost/panel/floor mode door actuator motor
- HVAC module - Electronic Manual Temperature Control (EMTC)
- HVAC module - Electronic Automatic Temperature Control (EATC)
- HVAC module - Dual Automatic Temperature Control (DATC)
- Stuck or bound linkage or door

PINPOINT TEST I: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET(S)

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I1 CHECK THE FEEDBACK POTENTIOMETER TOTAL RESISTANCE

- Disconnect: HVAC Module - DATC C2356a, HVAC Module - EATC C228a, or HVAC Module - EMTC C2357a.
- Measure the resistance between:

NOTE: EMTC systems only.

- HVAC module - EMTC C2357a-5, circuit LH111 (BN/WH), harness side and HVAC module - EMTC C2357a-15, circuit RH111 (GY/BU), harness side.

NOTE: EATC systems only.

- HVAC module - EATC C228a-5, circuit LH111 (BN/WH), harness side and HVAC module - EATC C228a-15, circuit RH111 (GY/BU), harness side.

NOTE: DATC systems only.

- HVAC module - DATC C2356a-5, circuit LH111 (BN/WH), harness side and HVAC module - DATC C2356a-15, circuit RH111 (GY/BU), harness side.

- Is the resistance between 4,000 and 6,000 ohms for EMTC/EATC systems or between 2,667 and 4,000 ohms for DATC systems?

Yes
GO to I2.

No
If resistance is greater than 4,000 ohms for EMTC/EATC systems or 6,000 ohms for DATC systems, GO to I4.

If resistance is less than 4,000 ohms for EMTC/EATC systems or 2,667 ohms for DATC systems, GO to I6.

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I2 CHECK THE POTENTIOMETER LOW-SIDE RESISTANCE

- Measure the resistance between:

NOTE: EMTC systems only.

- HVAC module - EMTC C2357a-15, circuit RH111 (GY/BU), harness side and HVAC module - EMTC C2357a-16, circuit VH436 (YE/VT), harness side.

NOTE: EATC systems only.

- HVAC module - EATC C228a-15, circuit RH111 (GY/BU), harness side and HVAC module - EATC C228a-16, circuit VH436 (YE/VT), harness side.

NOTE: DATC systems only.

- HVAC module - DATC C2356a-15, circuit RH111 (GY/BU), harness side and HVAC module - DATC C2356a-16, circuit VH436 (YE/VT), harness side.

- Is the resistance between 1 and 10,000 ohms?

Yes
GO to I3.

No
If the resistance is greater than 10,000 ohms, GO to I7.

If the resistance is less than 1 ohm, GO to I8.

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I3 CHECK THE POTENTIOMETER HIGH-SIDE RESISTANCE

- Measure the resistance between:

NOTE: EMTC systems only.

- HVAC module - EMTC C2357a-5, circuit LH111 (BN/WH), harness side and HVAC module - EMTC C2357a-16, circuit VH436 (YE/VT), harness side.

NOTE: EATC systems only.

- HVAC module - EATC C228a-5, circuit LH111 (BN/WH), harness side and HVAC module - EATC C228a-16, circuit VH436 (YE/VT), harness side.

NOTE: DATC systems only.

- HVAC module - DATC C2356a-5, circuit LH111 (BN/WH), harness side and HVAC module - DATC C2356a-16, circuit VH436 (YE/VT), harness side.

- Is the resistance between 1 and 10,000 ohms?

Yes
GO to I10.

No
If the resistance is greater than 10,000 ohms, INSTALL a new door actuator. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

If the resistance is less than 1 ohm, GO to I9.

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I4 CHECK CIRCUIT LH111 (BN/WH) FOR AN OPEN

NOTE: Due to limited connector accessibility, before carrying out this test step, visually inspect the wiring between the HVAC module and actuator for opens or shorts. If no damage is visually evident, proceed with the test.

- Disconnect: Defrost/Panel/Floor Door Actuator C2278.
- Measure the resistance between defrost/panel/floor door actuator C2278-10, circuit LH111 (BN/WH), harness side and:

NOTE: EMTC systems only.

- HVAC module - EMTC C2357a-5, circuit LH111 (BN/WH), harness side.

NOTE: EATC systems only.

- HVAC module - EATC C228a-5, circuit LH111 (BN/WH), harness side.

NOTE: DATC systems only.

- HVAC module - DATC C2356a-5, circuit LH111 (BN/WH), harness side.

- Is the resistance less than 5 ohms?

Yes
GO to I5.

No
REPAIR circuit LH111 (BN/WH) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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I5 CHECK THE ACTUATOR RETURN CIRCUIT RH111 (GY/BU) FOR AN OPEN

- Measure the resistance between defrost/panel/floor door actuator C2278-7, circuit RH111 (GY/BU), harness side and:

NOTE: EMTC systems only.

- HVAC module - EMTC C2357a-15, circuit RH111 (GY/BU), harness side.

NOTE: EATC systems only.

- HVAC module - EATC C228a-15, circuit RH111 (GY/BU), harness side.

NOTE: DATC systems only.

- HVAC module - DATC C2356a-15, circuit RH111 (GY/BU), harness side.

- Is the resistance less than 5 ohms?

Yes
INSTALL a new door actuator. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
REPAIR circuit RH111 (GY/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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I6 CHECK CIRCUITS RH111 (GY/BU) AND LH111 (BN/WH) FOR A SHORT TOGETHER

NOTE: Due to limited connector accessibility, before carrying out this test step, visually inspect the wiring between the HVAC module and actuator for opens or shorts. If no damage is visually evident, proceed with the test.

- Disconnect: Defrost/Panel/Floor Door Actuator C2278.
- Measure the resistance between:

NOTE: EMTC systems only.

- HVAC module - EMTC C2357a-5, circuit LH111 (BN/WH), harness side and HVAC module - EMTC C2357a-15, circuit RH111 (GY/BU), harness side.

NOTE: EATC systems only.

- HVAC module - EATC C228a-5, circuit LH111 (BN/WH), harness side and HVAC module - EATC C228a-15, circuit RH111 (GY/BU), harness side.

NOTE: DATC systems only.

- HVAC module - DATC C2356a-5, circuit LH111 (BN/WH), harness side and HVAC module - DATC C2356a-15, circuit RH111 (GY/BU), harness side.

- Is the resistance greater than 10,000 ohms?

Yes
INSTALL a new door actuator. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
REPAIR circuits RH111 (GY/BU) and LH111 (BN/WH) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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I7 CHECK CIRCUIT VH436 (YE/VT) FOR AN OPEN

NOTE: Due to limited connector accessibility, before carrying out this test step, visually inspect the wiring between the HVAC module and actuator for opens or shorts. If no damage is visually evident, proceed with the test.

- Disconnect: Defrost/Panel/Floor Door Actuator C2278.
- Measure the resistance between defrost/panel/floor door actuator C2278-9, circuit VH436 (YE/VT), harness side and:

NOTE: EMTC systems only.

- HVAC module - EMTC C2357a-16, circuit VH436 (YE/VT), harness side.

NOTE: EATC systems only.

- HVAC module - EATC C228a-16, circuit VH436 (YE/VT), harness side.

NOTE: DATC systems only.

- HVAC module - DATC C2356a-16, circuit VH436 (YE/VT), harness side.

- Is the resistance less than 5 ohms?

Yes
INSTALL a new door actuator. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
REPAIR circuit VH436 (YE/VT) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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I8 CHECK CIRCUITS RH111 (GY/BU) AND VH436 (YE/VT) FOR A SHORT TOGETHER

NOTE: Due to limited connector accessibility, before carrying out this test step, visually inspect the wiring between the HVAC module and actuator for opens or shorts. If no damage is visually evident, proceed with the test.

- Disconnect: Defrost/Panel/Floor Door Actuator C2278.
- Measure the resistance between:

NOTE: EMTC systems only.

- HVAC module - EMTC C2357a-15, circuit RH111 (GY/BU), harness side and HVAC module - EMTC C2357a-16, circuit VH436 (YE/VT), harness side.

NOTE: EATC systems only.

- HVAC module - EATC C228a-15, circuit RH111 (GY/BU), harness side and HVAC module - EATC C228a-16, circuit VH436 (YE/VT), harness side.

NOTE: DATC systems only.

- HVAC module - DATC C2356a-15, circuit RH111 (GY/BU), harness side and HVAC module - DATC C2356a-16, circuit VH436 (YE/VT), harness side.

- Is the resistance greater than 10,000 ohms?

Yes
INSTALL a new door actuator. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
REPAIR circuits RH111 (GY/BU) and VH436 (YE/VT) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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I9 CHECK CIRCUITS LH111 (BN/WH) AND VH436 (YE/VT) FOR A SHORT TOGETHER

NOTE: Due to limited connector accessibility, before carrying out this test step, visually inspect the wiring between the HVAC module and actuator for opens or shorts. If no damage is visually evident, proceed with the test.

- Disconnect: Defrost/Panel/Floor Door Actuator C2278.
- Measure the resistance between:

NOTE: EMTC systems only.

- HVAC module - EMTC C2357a-5, circuit LH111 (BN/WH), harness side and HVAC module - EMTC C2357a-16, circuit VH436 (YE/VT), harness side.

NOTE: EATC systems only.

- HVAC module - EATC C228a-5, circuit LH111 (BN/WH), harness side and HVAC module - EATC C228a-16, circuit VH436 (YE/VT), harness side.

NOTE: DATC systems only.

- HVAC module - DATC C2356a-5, circuit LH111 (BN/WH), harness side and HVAC module - DATC C2356a-16, circuit VH436 (YE/VT), harness side.

- NOTE: EMTC systems only.
- Measure the resistance between ground and the following:
- HVAC module - EMTC C2357a-5, circuit LH111 (BN/WH), harness side.
- HVAC module - EMTC C2357a-16, circuit VH436 (YE/VT), harness side.

EATC

- NOTE: EATC systems only.
- Measure the resistance between ground and the following:
- HVAC module - EATC C228a-5, circuit LH111 (BN/WH), harness side.
- HVAC module - EATC C228a-16, circuit VH436 (YE/VT), harness side.

DATC

- NOTE: DATC systems only.
- Measure the resistance between ground and the following:
- HVAC module - DATC C2356a-5, circuit LH111 (BN/WH), harness side.
- HVAC module - DATC C2356a-16, circuit VH436 (YE/VT), harness side.
- Is the resistance greater than 10,000 ohms?

Yes
GO to I11.

No
REPAIR circuit(s) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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I11 CHECK CIRCUITS RH111 (GY/BU) AND VH436 (YE/VT) FOR A SHORT TO POWER

- Ignition ON.

EMTC

- NOTE: EMTC systems only.
- Measure the voltage between ground and the following:
- HVAC module - EMTC C2357a-15, circuit RH111 (GY/BU), harness side.
- HVAC module - EMTC C2357a-16, circuit VH436 (YE/VT), harness side.

EATC

- NOTE: EATC systems only.
- Measure the voltage between ground and the following:
- HVAC module - EATC C228a-15, circuit RH111 (GY/BU), harness side.
- HVAC module - EATC C228a-16, circuit VH436 (YE/VT), harness side.

DATC

- Measure the voltage between ground and the following:

NOTE: DATC systems only.

- HVAC module - DATC C2356a-15, circuit RH111 (GY/BU), harness side.
- HVAC module - DATC C2356a-16, circuit VH436 (YE/VT), harness side.
- Is any voltage present?

Yes
REPAIR circuit(s) for a short to power. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
For EMTC systems, GO to I12.

For EATC systems, GO to I13.

For DATC systems, GO to I14.

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I12 CHECK THE DOOR ACTUATOR OPERATION

NOTE: If a jumper fuse opens while carrying out this test step, repair the circuit(s) for a short.

- Ignition ON.
- Measure the resistance between HVAC module - EMTC C2357a-15, circuit RH111 (GY/BU), harness side and HVAC module
- EMTC C2357a-16, circuit VH436 (YE/VT), harness side.

- Connect a fused jumper wire between:
- HVAC module - EMTC C2357a-1, circuit GD116 (BK/VT), harness side and HVAC module - EMTC C2357a-20, circuit CH228 (YE/GY), harness side.
- HVAC module - EMTC C2357a-26, circuit SBP07 (WH/RD), harness side and HVAC module - EMTC C2357a-14, circuit CH229 (WH/BU), harness side.

- Remove the fused jumpers.
- Connect a fused jumper wire between:
- HVAC module - EMTC C2357a-26, circuit SBP07 (WH/RD), harness side and HVAC module - EMTC C2357a-20, circuit CH228 (YE/GY), harness side.
- HVAC module - EMTC C2357a-1, circuit GD116 (BK/VT), harness side and HVAC module - EMTC C2357a-14, circuit CH229 (WH/BU), harness side.

- Connect a fused jumper wire between:
- HVAC module - EATC C228a-1, circuit GD116 (BK/VT), harness side and HVAC module - EATC C228a-20, circuit CH228 (YE/GY), harness side.
- HVAC module - EATC C228a-26, circuit SBP07 (WH/RD), harness side and HVAC module - EATC C228a-14, circuit CH229 (WH/BU), harness side.

- Remove the fused jumpers.
- Connect a fused jumper wire between:
- HVAC module - EATC C228a-26, circuit SBP07 (WH/RD), harness side and HVAC module - EATC C228a-20, circuit CH228 (YE/GY), harness side.
- HVAC module - EATC C228a-1, circuit GD116 (BK/VT), harness side and HVAC module - EATC C228a-14, circuit CH229 (WH/BU), harness side.

- Connect a fused jumper wire between:
- HVAC module - DATC C2356a-1, circuit GD116 (BK/VT), harness side and HVAC module - DATC C2356a-20, circuit CH228 (YE/GY), harness side.
- HVAC module - DATC C2356a-26, circuit SBP07 (WH/RD), harness side and HVAC module - DATC C2356a-14, circuit CH229 (WH/BU), harness side.

- Connect a fused jumper wire between:
- HVAC module - DATC C2356a-26, circuit SBP07 (WH/RD), harness side and HVAC module - DATC C2356a-20, circuit CH228 (YE/GY), harness side.
- HVAC module - DATC C2356a-1, circuit GD116 (BK/VT), harness side and HVAC module - DATC C2356a-14, circuit CH229 (WH/BU), harness side.

- Does the resistance smoothly increase and/or decrease when the jumpers are connected?

Yes
INSPECT for binding or broken door and linkage. If no condition is found, GO to I17.

No
GO to I15.

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I15 CHECK THE ACTUATOR MOTOR DRIVE CIRCUITS

- Measure the resistance between:

NOTE: EMTC systems only.

- HVAC module - EMTC C2357a-20, circuit CH228 (YE/GY), harness side and HVAC module - EMTC C2357a-14, circuit CH229 (WH/BU), harness side.

NOTE: EATC systems only.

- HVAC module - EATC C228a-20, circuit CH228 (YE/GY), harness side and HVAC module - EATC C228a-14, circuit CH229 (WH/BU), harness side.

NOTE: DATC systems only.

- HVAC module - DATC C2356a-20, circuit CH228 (YE/GY), harness side and HVAC module - DATC C2356a-14, circuit CH229 (WH/BU), harness side.

- Is the resistance between approximately 38-48 ohms?

Yes
INSPECT for binding or broken door and linkage. If no condition is found, INSTALL a new door actuator. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
GO to I16.

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I16 CHECK THE ACTUATOR MOTOR DRIVE CIRCUITS FOR AN OPEN

NOTE: Due to limited connector accessibility, before carrying out this test step, visually inspect the wiring between the HVAC module and actuator for opens or shorts. If no damage is visually evident, proceed with the test.

- Disconnect: Defrost/Panel/Floor Door Actuator C2278.
- Measure the resistance between defrost/panel/floor door actuator C2278-5, circuit CH228 (YE/GY), harness side and:

NOTE: EMTC systems only.

- HVAC module - EMTC C2357a-20, circuit CH228 (YE/GY), harness side.

NOTE: EATC systems only.

- HVAC module - EATC C228a-20, circuit CH228 (YE/GY), harness side.

NOTE: DATC systems only.

- HVAC module - DATC C2356a-20, circuit CH228 (YE/GY), harness side.

- Measure the resistance between defrost/panel/floor door actuator C2278-6, circuit CH229 (WH/BU), harness side and:

NOTE: EMTC systems only.

- HVAC module - EMTC C2357a-14, circuit CH229 (WH/BU), harness side.

NOTE: EATC systems only.

- HVAC module - EATC C228a-14, circuit CH229 (WH/BU), harness side.

NOTE: DATC systems only.

- HVAC module - DATC C2356a-14, circuit CH229 (WH/BU), harness side.

- Are the resistances less than 5 ohms?

Yes
INSTALL a new door actuator. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
REPAIR the circuit(s) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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I17 CHECK THE MODULE CONNECTION

- Carry out the HVAC Module Cold Boot Process. HVAC Module Cold Boot Process
- NOTE: DATC/EATC systems only.
- Carry out the HVAC Module - Electronic Automatic Temperature Control (EATC) and HVAC Module - Dual Automatic Temperature Control (DATC) On-Demand Self Test.
- Operate the system.
- Does the concern return?

Yes
INSTALL a new HVAC module. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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