U3003:62
Anti-Lock Control
Pinpoint Test I: DTCs U3003:16, 17 and 62
Refer to Wiring Diagrams Set 42, Vehicle Dynamic Systems for schematic and connector information. Electrical Diagrams
Normal Operation
The voltage required for correct ABS operation is between 10 and 18 volts. Fused battery voltage is supplied to the ABS module from Battery Junction Box (BJB) fuse 12 (30A) along circuit 30-CF13 (RD), BJB (Battery Junction Box) fuse 15 (20A) along circuit 30-CF6 (RD). Fused ignition voltage is supplied to the ABS module from Central Junction Box (CJB) fuse 161 (7.5A) along circuit 15-CF6 (GN/YE). Ground is provided along circuit 91-CF6 (BK/YE) and circuit 91-CF13 (BK/BU).
- DTC U3003:16 (Battery Voltage: Circuit Voltage Below Threshold)- If the voltage on circuit 30-CF13 (RD), 30-CF6 (RD) or 15-CF6 (GN/YE) is below 10 volts, this DTC will set.
- DTC U3003:17 (Battery Voltage: Circuit Voltage Above Threshold)- If the voltage on circuit 30-CF13 (RD), 30-CF6 (RD) or 15-CF6 (GN/YE) is above 17 volts, this DTC will set.
- DTC U3003:62 (Battery Voltage: Signal Compare Failure)- The ABS module compares measured input voltage with the battery voltage that is broadcast on the High Speed Controller Area Network (HS-CAN). If the measured voltage at the ABS module does not match the battery voltage reported by other modules on the bus, this DTC will set.
This pinpoint test is intended to diagnose the following:
- Charging system
- Fuses
- Battery
- Wiring, terminals or connectors
- ABS module
PINPOINT TEST I : DTCs U3003:16, 17 AND 62
NOTE: DTCs U3003:16 and 17 can set if the vehicle has been recently jump started, the 12-volt battery has been recently charged or the 12-volt battery has been discharged. The 12-volt 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
NOTE: This vehicle has an in-line test connector C126 which may make circuit testing easier in certain situations.
Refer to Wiring Diagrams Set 42 for schematic and connector information. Electrical Diagrams
I1 RETRIEVE ALL CMDTCs (Continuous Memory Diagnostic Trouble Codes) IN ALL MODULES
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test- All CMDTCs (Continuous Memory Diagnostic Trouble Codes).
Is DTC U3003:16 or 17, DTCs B1317, B1318 and/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
For DTC U3003:16 or 17, GO to I3.
For DTC U3003:62, GO to I2.
I2 CHECK THE ABS MODULE DTCs
- Review the ABS module DTCs retrieved during Inspection and Verification.
Are any ABS module DTCs present other than U3003:62?
Yes
GO to the ABS Module DTC Chart to diagnose the ABS module DTCs. Antilock Brakes / Traction Control Systems
No
GO to I3.
I3 CHECK CHARGING SYSTEM VOLTAGE
- Start the vehicle, verify that the ready indicator is illuminated.
- Measure the voltage of the battery with and without a load on the charging system as follows:
- Turn off all accessories and measure battery voltage.
- Turn on headlights and HVAC fan on high and measure battery voltage.
Are the voltages between 13 and 15.2 volts?
Yes
GO to I4.
No
REFER to Charging System to diagnose the charging system. CLEAR all Continuous Memory Diagnostic Trouble Codes (CMDTCs). TEST the system for normal operation.
I4 CHECK THE ABS MODULE GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: ABS Module C155.
- Measure the resistance between ground and:
- ABS module C155-16, circuit 91-CF6 (BK/YE), harness side.
- ABS module C155-47, circuit 91-CF13 (BK/BU), harness side.
- Repeat this measurement while wiggling the harness.
Is the resistance less than 5 ohms?
Yes
GO to I5.
No
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
I5 CHECK FOR VOLTAGE AT THE ABS MODULE
- Ignition ON.
- Measure the voltage between ground and:
- ABS module C155-1, 30-CF13 (RD), harness side.
- ABS module C155-32, 30-CF6 (RD), harness side.
- ABS module C155-8, 15-CF6 (GN/YE), harness side.
Are the voltages greater than 10 volts?
Yes
GO to I6.
No
VERIFY that BJB (Battery Junction Box) fuses 12 (30A), 15 (20A) and CJB (Central Junction Box) fuse 161 (7.5A) are OK. If OK, REPAIR the affected circuit(s).
If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Electrical Diagrams
CLEAR the DTCs and REPEAT the self-test.
I6 CHECK FOR CORRECT ABS MODULE OPERATION
- Ignition OFF.
- Disconnect: In-line Connector C126.
- Check ABS module C155 and in-line connector C126 for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: In-line Connector C126.
- Connect: ABS Module C155.
- Make sure the connector seats correctly, then operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new Hydraulic Control Unit (HCU). REFER to Hydraulic Control Unit (HCU) . 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.