Pinpoint Test Q: Temperature Control Is Inoperative/Does Not Operate Correctly - EATC/DATC

Climate Control System

Pinpoint Tests

Pinpoint Test Q: Temperature Control is Inoperative/Does Not Operate Correctly - EATC/DATC

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 blend door actuator, the HVAC module supplies voltage to the blend door actuator motors through the door actuator feed A circuits, and supplies ground through the door actuator feed B circuits. To reverse the blend door actuator rotation, the HVAC module reverses the voltage and ground circuits.

The blend door actuator feedback resistors are supplied a ground from the HVAC module by the blend door actuator return circuits and a 5-volt reference voltage on the blend door actuator reference circuits. The HVAC module reads the voltage on the blend door actuator feedback circuits to determine the blend door actuator position, by the position of the actuator feedback resistor wiper arm.

Door actuator feed A circuits
- (Dual Automatic Temperature Control (DATC)/Electronic Automatic Temperature Control (EATC)) LH Blend - CH238 (YE/OG)
- RH Blend - CH212 (BU/OG)

Door actuator feed B circuits
- (DATC/EATC) LH Blend - CH239 (BU/WH)
- RH Blend - CH213 (BN/GN)

Door actuator return circuits
- LH Blend - RH111 (GY/BU)
- RH Blend - RH111 (GY/BU)

Door actuator reference circuits
- LH Blend - LH111 (BN/WH)
- RH Blend - LH111 (BN/WH)

Door actuator feedback circuits
- (DATC/EATC) LH Blend - VH440 (BN/BU)
- RH Blend - VH441 (WH/BN)

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Blend door actuator motor
- HVAC module - EATC
- HVAC module - DATC
- Stuck or bound linkage or door

PINPOINT TEST Q: TEMPERATURE CONTROL IS INOPERATIVE/DOES NOT OPERATE CORRECTLY -
EATC/DATC

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Q1 CHECK THE FEEDBACK POTENTIOMETER TOTAL RESISTANCE

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

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 EATC systems or between 2,667 and 4,000 ohms for DATC systems?

Yes
GO to Q2.

No
For EATC systems, if resistance is greater than 4,000 ohms, GO to Q4.

For EATC systems, if resistance is less than 4,000 ohms, GO to Q6.

For DATC systems, if resistance is greater than 6,000 ohms, GO to Q4.

For DATC systems, If resistance is less than 2,667 ohms, GO to Q6.

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Q2 CHECK THE POTENTIOMETER LOW-SIDE RESISTANCE

EATC

- NOTE: EATC systems only.
- Measure the resistance between HVAC module - EATC C228a-15, circuit RH111 (GY/BU), harness side and HVAC module - EATC C228a-18, circuit VH439 (GY/VT), harness side.

DATC

- NOTE: EATC systems only.
- Measure the resistance between HVAC module - EATC C228a-5, circuit LH111 (BN/WH), harness side and HVAC module - EATC C228a-18, circuit VH439 (GY/VT), harness side.

DATC

- NOTE: DATC systems only.
- Measure the resistance between HVAC module - DATC C2356a-5, circuit LH111 (BN/WH), harness side and the following:
- For DTC B2266, HVAC module - DATC C2356a-18, circuit VH440 (BN/BU), harness side.
- For DTC B2267, HVAC module - DATC C2356a-17, circuit VH441 (WH/BN), harness side.
- Is the resistance between 1 and 10,000 ohms?

Yes
GO to Q10.

No
If resistance is greater than 10,000 ohms, INSTALL a new door actuator. TEST the system for normal operation.

If resistance is less than 1 ohm, GO to Q9.

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Q4 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: For DTC B2266, LH Blend Door Actuator C2091.
- Disconnect: For DTC B2267, RH Blend Door Actuator C2092.

EATC

- NOTE: EATC systems only.
- Measure the resistance between HVAC module - EATC C228a-5, circuit LH111 (BN/WH), harness side and LH blend door actuator C2091-10, circuit LH111 (BN/WH), harness side.

DATC

- NOTE: DATC systems only.
- Measure the resistance between HVAC module - DATC C2356a-5, circuit LH111 (BN/WH), harness side and the following:
- For DTC B2266, LH blend door actuator C2091-10, circuit LH111 (BN/WH), harness side.
- For DTC B2267, RH blend door actuator C2092-10, circuit LH111 (BN/WH), harness side.
- Is the resistance less than 5 ohms?

Yes
GO to Q5.

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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Q5 CHECK THE ACTUATOR RETURN CIRCUIT RH111 (GY/BU) FOR AN OPEN

EATC

- NOTE: EATC systems only.
- Measure the resistance between HVAC module - EATC C228a-15, circuit RH111 (GY/BU), harness side and LH blend door actuator C2091-7, circuit RH111 (GY/BU), harness side.

DATC

- NOTE: DATC systems only.
- Measure the resistance between HVAC module - DATC C2356a-15, circuit RH111 (GY/BU), harness side and the following:
- For DTC B2266, LH blend door actuator C2091-7, circuit RH111 (GY/BU), harness side.
- For DTC B2267, RH blend door actuator C2092-7, 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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Q6 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: For DTC B2266, LH Blend Door Actuator C2091.
- Disconnect: For DTC B2267, RH Blend Door Actuator C2092.

EATC

- NOTE: EATC systems only.
- Measure the resistance between HVAC module - EATC C228a-5, circuit LH111 (BN/WH), harness side and HVAC module - EATC C228a-15, circuit RH111 (GY/BU), harness side.

DATC

- NOTE: DATC systems only.
- Measure the resistance between 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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Q7 CHECK CIRCUIT VH440 (BU/BN), VH441 (WH/BN) OR VH439 (GY/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: For DTC B2266, LH Blend Door Actuator C2091.
- Disconnect: For DTC B2267, RH Blend Door Actuator C2092.

EATC

- NOTE: EATC systems only.
- Measure the resistance between HVAC module - EATC C228a-18, circuit VH439 (GY/VT), harness side and LH blend door actuator C2091-9, circuit VH439 (GY/VT), harness side.

DATC, DTC B2266

- NOTE: DATC systems only.
- NOTE: For DTC B2266
- Measure the resistance between HVAC module - DATC C2356a-18 , circuit VH440 (BU/BN), harness side and LH blend door actuator C2091-9, circuit VH440 (BU/BN), harness side.

DATC, DTC B2267

- NOTE: DATC systems only.
- NOTE: For DTC B2267
- Measure the resistance between HVAC module - DATC C2356a-17, circuit VH441 (WH/BN), harness side and RH blend door actuator C2092-9, circuit VH441 (WH/BN), 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 VH440 (BU/BN), VH441 (WH/BN) or VH439 (GY/VT) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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Q8 CHECK CIRCUIT RH111 (GY/BU) FOR A SHORT TO CIRCUIT VH440 (BU/BN), VH441 (WH/BN) OR VH439 (GY/VT)

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: For DTC B2266, LH Blend Door Actuator C2091.
- Disconnect: For DTC B2267, RH Blend Door Actuator C2092.

EATC

- NOTE: DATC systems only.
- Measure the resistance between HVAC module - DATC C2356a-15, circuit RH111 (GY/BU), harness side and the following:
- For DTC B2266, HVAC module - DATC C2356a-18, circuit VH440 (BU/BN), harness side.
- For DTC B2267, HVAC module - DATC C2356a-17, circuit VH441 (WH/BN), 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 VH440 (BU/BN), VH441 (WH/BN) or VH439 (GY/VT) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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Q9 CHECK CIRCUIT LH111 (BN/WH) FOR A SHORT TO CIRCUIT VH440 (BU/BN), VH441 (WH/BN) OR VH439 (GY/VT)

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: For DTC B2266, LH Blend Door Actuator C2091.
- Disconnect: For DTC B2267, RH Blend Door Actuator C2092.

EATC

- NOTE: DATC systems only.
- Measure the resistance between HVAC module - DATC C2356a-5, circuit LH111 (BN/WH), harness side and the following:
- For DTC B2266, HVAC module - DATC C2356a-18, circuit VH440 (BU/BN), harness side.
- For DTC B2267, HVAC module - DATC C2356a-17, circuit VH441 (WH/BN), 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 LH111 (BN/WH) and VH440 (BU/BN), VH441 (WH/BN) or VH439 (GY/VT) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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Q10 CHECK CIRCUIT LH111 (BN/WH), VH439 (GY/VT), VH440 (BU/BN) OR VH441 (WH/BN) FOR A SHORT TO GROUND

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-18, circuit VH439 (GY/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.
- For DTC B2266, HVAC module - DATC C2356a-18, circuit VH440 (BU/BN), harness side.
- For DTC B2267, HVAC module - DATC C2356a-17, circuit VH441 (WH/BN), harness side.
- Is the resistance greater than 10,000 ohms?

Yes
GO to Q11.

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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Q11 CHECK CIRCUIT RH111 (GY/BU), VH439 (GY/VT), VH440 (BU/BN) OR VH441 (WH/BN) FOR A SHORT TO POWER

- Ignition ON.

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-18, circuit VH439 (GY/VT), harness side.

DATC

- NOTE: DATC systems only.
- Measure the voltage between ground and the following:
- HVAC module - DATC C2356a-15, circuit RH111 (GY/BU), harness side.
- For DTC B2266, HVAC module - DATC C2356a-18, circuit VH440 (BU/BN), harness side.
- For DTC B2267, HVAC module - DATC C2356a-17, circuit VH441 (WH/BN), 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 EATC systems, GO to Q12.

For DATC systems, DTC B2266, GO to Q13.

For DATC systems, DTC B2267, GO to Q14.

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Q12 CHECK THE DOOR ACTUATOR OPERATION

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

- Measure the resistance between HVAC module - EATC C228a-15, circuit RH111 (GY/BU), harness side and HVAC module - EATC C228a-18, circuit VH439 (GY/VT), harness side.

- Connect a fused jumper wire between:
- HVAC module - EATC C228a-26, circuit SBP07 (WH/RD), harness side and HVAC module - EATC C228a-6, circuit CH234 (YE/GN), harness side.
- HVAC module - EATC C228a-1, circuit GD116 (BK/VT), harness side and HVAC module - EATC C228a-7, circuit CH233 (VT/BN), 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-7, circuit CH233 (VT/BN), harness side.
- HVAC module - EATC C228a-1, circuit GD116 (BK/VT), harness side and HVAC module - EATC C228a-6, circuit CH234 (YE/GN), 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 Q17.

No
GO to Q15.

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Q13 CHECK THE DOOR ACTUATOR OPERATION

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

- Measure the resistance between HVAC module - DATC C2356a-15, circuit RH111 (GY/BU), harness side and HVAC module - DATC C2356a-18, circuit VH440 (BN/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-6, circuit CH239 (BU/WH), harness side.
- HVAC module - DATC C2356a-1, circuit GD116 (BK/VT), harness side and HVAC module - DATC C2356a-7, circuit CH238 (YE/OG), harness side.

- Remove the fused jumpers.
- Connect a fused jumper wire between:
- HVAC module - DATC C2356a-26, circuit SBP07 (WH/RD), harness side and HVAC module - DATC C2356a-7, circuit CH238 (YE/OG), harness side.
- HVAC module - DATC C2356a-1, circuit GD116 (BK/VT), harness side and HVAC module - DATC C2356a-6, circuit CH239 (BU/WH), 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 Q17.

No
GO to Q15.

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Q14 CHECK THE DOOR ACTUATOR OPERATION

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

- Measure the resistance between HVAC module - DATC C2356a-15, circuit RH111 (GY/BU), harness side and HVAC module - DATC C2356a-17, circuit VH441 (WH/BN), harness side.

- Connect a fused jumper wire between:
- HVAC module - DATC C2356a-26, circuit SBP07 (WH/RD), harness side and HVAC module - DATC C2356a-24, circuit CH213 (BN/GN), harness side.
- HVAC module - DATC C2356a-1, circuit GD116 (BK/VT), harness side and HVAC module - DATC C2356a-25, circuit CH212 (BU/OG), harness side.

- Remove the fused jumpers.
- Connect a fused jumper wire between:
- HVAC module - DATC C2356a-26, circuit SBP07 (WH/RD), harness side and HVAC module - DATC C2356a-25, circuit CH212 (BU/OG), harness side.
- HVAC module - DATC C2356a-1, circuit GD116 (BK/VT), harness side and HVAC module - DATC C2356a-24, circuit CH213 (BN/GN), harness side.

- NOTE: EATC systems only.
- Measure the resistance between HVAC module - EATC C228a-6, circuit CH234 (YE/GN), harness side and HVAC module - EATC C228a-7, circuit CH233 (VT/BN), harness side.

DATC, DTC B2266

- NOTE: DATC systems only.
- NOTE: For DTC B2266
- Measure the resistance between HVAC module - DATC C2356a-7, circuit CH238 (YE/OG), harness side and HVAC module - DATC C2356a-6, circuit CH239 (BU/WH), harness side.

DATC, DTC B2267

- NOTE: DATC systems only.
- NOTE: For DTC B2267
- Measure the resistance between HVAC module - DATC C2356a-25, circuit CH212 (BU/OG), harness side and HVAC module - DATC C2356a-24, circuit CH213 (BN/GN), harness side.
- Is the resistance between approximately 59-73 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 Q16.

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Q16 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: For DTC B2266, LH Blend Door Actuator C2091.
- Disconnect: For DTC B2267, RH Blend Door Actuator C2092.

EATC

- NOTE: EATC systems only.
- Measure the resistance between the HVAC module - EATC connector, harness side and LH blend door actuator, harness side using the following chart.

DATC

- NOTE: DATC systems only.
- Measure the resistance between the HVAC module - DATC connector, harness side and LH blend door actuator, harness side or RH blend door actuator, harness side using the following chart.

B2266-B2267:

- Are the resistances less than 5 ohms?

Yes
INSPECT for binding or broken 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
REPAIR the circuit(s) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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Q17 CHECK THE MODULE CONNECTION

- Carry out the HVAC Module Cold Boot Process. HVAC Module Cold Boot Process
- 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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