Pinpoint Test I: DTCs U3003:16 and 17
Climate Control System
Pinpoint Tests
Pinpoint Test I: DTCs U3003:16 and 17
Refer to Wiring Diagram Set 55, Automatic Climate Control System for schematic and connector information. Diagrams By Number
NOTE: DTC U3003 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.
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). The Rear Heating Ventilation Air Conditioning (RHVAC) module receives a ground through circuit GD114 (BK/BU). The RHVAC module is supplied constant battery voltage through circuit SBP16 (VT/RD).
- DTC U3003:16 (Control Module Input Power "A": Circuit Voltage Below Threshold) - The module senses when battery voltage is less than 9 volts.
- DTC U3003:17 (Control Module Input Power "A": Circuit Voltage Above Threshold) - The module senses when battery voltage is greater than 16 volts.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- HVAC module
- RHVAC module
PINPOINT TEST I: DTCs U3003:16 AND 17
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I1 RETRIEVE ALL CMDTCs IN ALL MODULES
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - All CMDTCs.
- Is DTC B1317, B1318 or B1676 present in one or more modules and DTC 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 I2.
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I2 CHECK BATTERY CONDITION
- Ignition OFF.
- Refer to Battery and carry out the Pinpoint Test A: 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 Continuous Memory Diagnostic Trouble Codes (CMDTCs). TEST the system for normal operation.
If the battery passed the condition test and did not require a recharge, GO to I3.
No
INSTALL a new battery. CLEAR all CMDTCs. REPEAT the self-test. TEST the system for normal operation.
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I3 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 U3003:17, turn off all accessories and run the engine at 1,500 rpm for a minimum of 2 minutes.
- For DTC U3003:16, 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 U3003:16, GO to I4.
For DTC U3003:17, INSTALL a new HVAC module. CLEAR all CMDTCs. REPEAT the self-test. TEST the system for normal operation.
No
REFER to Charging System to diagnose the charging system. CLEAR all CMDTCs. REPEAT the self-test. TEST the system for normal operation.
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I4 CHECK CIRCUITS SBP15 (WH/RD) AND SBP16 (VT/RD) FOR AN OPEN
- Ignition OFF.
- Disconnect: HVAC Module C2356A or RHVAC C3198.
- Ignition ON.
For HVAC module
- For HVAC module, with the engine running, measure the voltage between ground and HVAC module C2356A-1, circuit SBP15 (WH/RD), harness side.
For RHVAC module
- For RHVAC module, with the engine running, measure the voltage between ground and RHVAC module C3198-6, circuit SBP16 (VT/RD), harness side.
- Is the voltage greater than 10 volts?
Yes
GO to I5.
No
VERIFY Smart Junction Box (SJB) fuses 15 (10A) and 16 (15A) are OK. If OK, REPAIR circuit SBP15 (WH/RD) or SBP16 (VT/RD) for an open. CLEAR all CMDTCs. REPEAT the self-test. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number
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I5 CHECK CIRCUIT GD114 (BK/BU) FOR AN OPEN
- Ignition OFF.
For HVAC module
- For HVAC module, with the resistance between ground and HVAC module C2356A-17, circuit GD114 (BK/BU), harness side.
For RHVAC module
- For RHVAC module, with the resistance between ground and RHVAC module C3198-5, circuit GD114 (BK/BU), harness side.
- Repeat the measurement while wiggling the harness.
- Is the resistance less than 5 ohms?
Yes
GO to I6.
No
REPAIR circuit GD114 (BK/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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I6 CHECK THE HVAC MODULE CONNECTION
- Inspect the module connectors for:
- corrosion.
- pushed-out terminals.
- damaged terminals.
- Connect and correctly seat all the HVAC module connectors.
- Clear the DTCs.
- Operate the system and verify the concern is still present.
- Is the concern still present?
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.
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