Pinpoint Test R: DTC U3006
Climate Control System
Pinpoint Tests
Pinpoint Test R: DTC U3006
Refer to Wiring Diagram Set 55, Automatic Climate Control System for schematic and connector information. Diagrams By Number
NOTE: DTC U3006 can be set if the vehicle has been recently jump started, the battery has been recently charged or the battery has been discharged. The battery may become discharged due to excessive load(s) on the charging system from aftermarket accessories or if the battery has been left unattended with the accessories on.
NOTE: Carry out a thorough inspection and verification before proceeding with the pinpoint test. Refer to Inspection and Verification. Inspection And Verification
Normal Operation
Under normal operation, the HVAC module receives a ground through circuit GD114 (BK/BU). The HVAC module is supplied constant battery voltage through circuit SBP15 (WH/RD) and ignition switched voltage through circuit CBP37 (WH).
- DTC U3006:1A Control Module Input Power "A": Circuit Voltage Below Threshold - The module senses when battery voltage is greater than 16 volts.
- DTC U3006:1B Control Module Input Power "A": Circuit Voltage Above Threshold - The module senses when battery voltage is less than 9 volts.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- HVAC module
PINPOINT TEST R: U3006
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R1 RETRIEVE ALL CMDTCs IN ALL MODULES
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - All Continuous Memory Diagnostic Trouble Codes (CMDTCs).
- Is B1317, B1318 or B1676 present in one or more modules AND P0563, P0620, P0625, P0626 or P065B present in the PCM?
Yes
REFER to Charging System for diagnosis of the battery and charging system.
No
GO to R2.
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R2 CHECK BATTERY CONDITION
- Ignition OFF.
- Refer to Battery and carry out the Battery - Condition Test. Pinpoint Tests
- Does the battery pass the condition test?
Yes
If the battery passed the condition test but required a recharge, REFER to Charging System to diagnose the charging system. CLEAR all CMDTCs. TEST the system for normal operation.
If the battery passed the condition test and did not require a recharge, GO to R3.
No
INSTALL a new battery. CLEAR all CMDTCs. TEST the system for normal operation.
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R3 CHECK THE CHARGING SYSTEM VOLTAGE
NOTE: Do not allow the engine rpm to increase above 2,000 rpm while performing this step or the generator may self excite and result in default charging system output voltage. If engine rpm has gone above 2,000 rpm, shut the vehicle OFF and restart the engine before performing this step.
- Start the engine.
- Measure the voltage of the battery:
- For DTC U3006:1A, turn off all accessories and run the engine at 1,500 rpm for a minimum of 2 minutes.
- For DTC U3006:1B, turn on headlights and HVAC fan on high and run engine at 1,500 rpm for a minimum of 2 minutes.
- Is the battery voltage between 13-15.2 volts?
Yes
For DTC U3006:1B, GO to R4.
For DTC U3006:1A, INSTALL a new HVAC module. CLEAR all CMDTCs. REPEAT the self-test.
No
REFER to Charging System to diagnose the charging system. CLEAR all CMDTCs. TEST the system for normal operation.
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R4 CHECK CIRCUITS SBP15 (WH/RD) AND CBP37 (WH) FOR AN OPEN
- Ignition OFF.
- Disconnect: HVAC Module C228a/C2356a.
- Ignition ON.
- With the engine running, measure the voltage between HVAC module C228a/C2356a-13, circuit SBP15 (WH/RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to R5.
No
VERIFY Smart Junction Box (SJB) fuse 15 (10A) is OK. If OK, REPAIR circuit SBP15 (WH/RD) for an open. CLEAR all CMDTCs. REPEAT the self-test. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short.
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R5 CHECK CIRCUIT GD114 (BK/BU) FOR AN OPEN
- Ignition OFF.
- Measure the resistance between HVAC module C228a/C2356a-23, circuit GD114 (BK/BU), harness side and ground.
- Repeat this measurement while wiggling the harness.
- Is the resistance less than 5 ohms?
Yes
GO to R6.
No
REPAIR circuit GD114 (BK/BU) for an open. TEST the system for normal operation.
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R6 CHECK MODULE CONNECTION
- Carry out the HVAC Module Cold Boot Process. HVAC Module Cold Boot Process
- Carry out the HVAC Module On-Demand Self Test. Alternate Diagnostic Methods - HVAC Module
- 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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