U1002 on 2006-2010 Infiniti M45: CAN Communication Failure Causes and Fixes

What's Unique About the 2006-2010 Infiniti M45

The 2006-2010 Infiniti M45 (Y50 generation) relies on a complex network of modules for its luxury and performance features. Like many Nissan and Infiniti vehicles from this era, its electronics are sensitive to voltage and ground integrity. The popularity of aftermarket grounding kits on forums highlights the community's awareness of the factory system's potential weakness. While not having the same documented BCM water leak issues as the G37, the M45 is highly prone to network codes like U1002 being triggered by simple electrical foundation problems, such as corroded ground straps, a failing battery, or a faulty IPDM, rather than a catastrophic module failure.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Multiple warning lights on the dashboard, especially VDC OFF, SLIP, and ABS
• Vehicle fails to start or stalls intermittently, sometimes at highway speeds.
• Engine cranks but will not fire (a classic symptom of IPDM failure).
• Gauges on the instrument cluster behave erratically or stop working
• Transmission may not shift correctly or may enter a limp mode
• Loss of power steering assist (if equipped with electric/electronic power steering)
• Erratic electrical behavior, such as headlights or wipers acting on their own.

Most Likely Causes

1. Low Battery Voltage or Failing Alternator 🔴 High Probability → Shop Vehicle Battery Infiniti's electronic modules are highly sensitive to system voltage. A weak battery or poor charging system output can cause modules to drop off the network and trigger communication codes. TSBs consistently list checking voltage as the first step.
   How to confirm: Test the battery voltage with the engine off; it should be above 12.4V. With the engine running, alternator output should be between 13.5V and 14.8V. A load test is the most definitive way to confirm battery health.
   Typical fix: Charge or replace the battery. If the alternator is faulty, it will need to be replaced.
   Est. part cost: $150-$450
2. Corroded or Loose Ground Wires 🔴 High Probability The main battery-to-chassis ground and engine block grounds are known to corrode, creating high resistance that disrupts module communication. This is a very common cause for U-codes on Nissan and Infiniti platforms, to the point that aftermarket grounding kits are a popular modification.
   How to confirm: Visually inspect the main negative battery cable connection to the chassis and other ground straps in the engine bay. Perform a voltage drop test from the battery negative post to the chassis and engine block; the reading should be less than 0.2V with the engine running.
   Typical fix: Disconnect the ground wires, use a wire brush to clean the cable ends and the chassis/engine mounting points to bare metal, then re-secure them tightly. Applying dielectric grease can prevent future corrosion.
   Est. part cost: $5-$50
3. Failing ABS / VDC Actuator Control Unit 🟡 Medium Probability The ABS/VDC module is a critical node on the CAN bus. An internal failure in this module can disrupt the entire network, causing other modules to report communication loss. This is a common point of failure leading to the trifecta of ABS, VDC OFF, and SLIP lights. 🎬 Watch: Common symptoms and fixes for a failing ABS module.
   How to confirm: Use an advanced scan tool to see if the ABS module is the one that is not communicating. Try to communicate directly with the ABS module. If it's unresponsive but has good power and ground, it is likely faulty.
   Typical fix: Replace the ABS actuator and control unit assembly. This often requires programming and a brake fluid bleed procedure.
   Est. part cost: $400-$1200
4. Faulty Intelligent Power Distribution Module (IPDM) 🟡 Medium Probability → Shop Fuse Box The IPDM is a known weak point. It contains non-serviceable internal relays (especially for the fuel pump) that fail, causing a crank-no-start condition and CAN codes. Water intrusion from clogged cowl drains is a common cause of failure.
   How to confirm: If the car cranks but won't start, the IPDM is a primary suspect. An advanced scanner may show U-codes from multiple modules. Some models have a built-in self-test that can be activated by a sequence of door switch presses, which cycles outputs like wipers and lights to confirm IPDM function.
   Typical fix: Replace the IPDM. It is located in the engine bay fuse box. 🎬 See this guide for all M45 fuse and relay locations. Used units can be plug-and-play if the part number is an exact match.
   Est. part cost: $75-$400

Rare But Worth Checking

• Damaged CAN Bus Wiring Harness: Wiring can be damaged by previous repairs, rodent activity, or chafing against chassis components. A visual inspection of the harness, particularly around the ECM, BCM, and ABS module, may reveal issues.
• Faulty ECM or BCM: While less common than wiring or ground issues, the Engine Control Module (ECM) or Body Control Module (BCM) can fail internally and bring down the network. These are terminating modules for the CAN bus. This should only be considered after all other possibilities are exhausted.

Diagnosis Steps

1. Check and record all DTCs from all available modules using an advanced scan tool like Infiniti CONSULT.
2. CRITICAL STEP: Test the battery and charging system. Ensure voltage is stable and above 12.4V with the engine off. Low voltage is a primary cause of U-codes.
3. Inspect and thoroughly clean all major ground connections, especially the battery-to-chassis ground and engine-to-chassis straps. Perform a voltage drop test to confirm ground integrity.
4. With the battery disconnected, measure the resistance between Pin 6 (CAN-H) and Pin 14 (CAN-L) at the OBD-II port. A healthy network should read approximately 60 ohms. A reading of 120 ohms indicates an open circuit or a missing terminating resistor (a module is unplugged or has failed). A reading near 0 ohms indicates a short circuit between the CAN-H and CAN-L wires.
5. If the resistance is incorrect, begin disconnecting modules one by one (starting with the ABS, then IPDM, then ECM) to see if the resistance returns to a normal value, which can help isolate a faulty module or wiring branch.
6. If resistance is normal but the problem persists, use an oscilloscope to check the CAN signal waveform at the OBD-II port. Look for clean, mirroring square waves.
7. If a specific module is suspected (e.g., the ABS actuator), verify it has proper power and ground at its connector using a multimeter before condemning the module.

Parts You'll Likely Need

• Battery — A weak or failing battery is a primary cause of intermittent communication faults on this platform.
  Trusted brands: Interstate, DieHard, Bosch
  OEM price range: $200-$300
  Aftermarket price range: $150-$250
• ABS Actuator and Control Unit (OEM #47660-EH10D, 47660-EH113, 47660-EH64B (Varies by RWD/AWD and options, verify with VIN)) — This module is a common point of failure that can disrupt the entire CAN network, leading to a U1002 code.
  Trusted brands: Hitachi, Bosch (OEM supplier)
  OEM price range: $800-$1500
  Aftermarket price range: $400-$900
• Intelligent Power Distribution Module (IPDM) (OEM #284B7-EG01A (Example, part number must be an exact match)) — Internal relay failure is common, leading to crank-no-start conditions and network codes.
  Trusted brands: Infiniti OE
  OEM price range: $300-$500
  Aftermarket price range: $75-$200 (Used OEM)
• Ground Cable/Strap — Corrosion on the factory ground points is extremely common. Cleaning is often sufficient, but a heavily corroded cable may need replacement.

Related Codes That Often Appear With This One

• U1000 — U1000 is a general CAN communication failure code. U1002 is a more specific version with stricter timing criteria, and they frequently appear together as they indicate the same type of network fault.
• U1001 — This code specifically points to a communication loss with the ECM. It often accompanies other CAN codes when the network is unstable.
• C1109 — This code indicates a power supply issue (low voltage) to the ABS actuator. It can be a direct result of a failing battery or a precursor to the ABS module failing and causing network codes like U1002.

Technical Service Bulletins (TSBs) & Recalls

• ITB10-029A: Provides diagnostic tips and guidelines for CAN communication codes U1000, U1001, U1002, and U1010, emphasizing that U1002 has a tighter specification than U1000 and that basic electrical checks (power, ground, and CAN resistance) are critical before replacing modules.

Platform-Specific Known Issues

• IPDM Failure from Water Intrusion: The IPDM, located in the engine bay, is susceptible to failure caused by water leaking from clogged cowl drains. This can cause a host of electrical problems, including the U1002 code and a crank-no-start condition.

Mechanic-Grade Diagnostic Values

• CAN Bus Resistance at OBD-II Port (Battery Disconnected) — expected: ~60 Ohms (± 2-3 Ohms). Failure: 120 Ohms indicates a missing terminating resistor or open circuit. ~0 Ohms indicates a short between CAN-H and CAN-L.
• CAN-High Voltage to Ground (Key On, Engine Off) — expected: ~2.5V to 3.0V. Failure: Voltage outside this range, or 0V, indicates a short or open on the CAN-H line. A steady 2.5V on both lines can indicate they are shorted together.
• CAN-Low Voltage to Ground (Key On, Engine Off) — expected: ~2.0V to 2.5V. Failure: Voltage outside this range, or 0V, indicates a short or open on the CAN-L line. The sum of CAN-H and CAN-L voltages should be approximately 5V.

Scan Tool Commands That Help

• Infiniti CONSULT-II / CONSULT-III: Self-Diagnostic Results — To view which specific modules are reporting the U1002 code. This is the first step to understanding which module is 'deaf' versus which one is 'mute'.
• Infiniti CONSULT-II / CONSULT-III: CAN Diag Support Monitor — To see a live status of which modules are actively communicating on the network. This helps identify a module that is intermittently dropping out.
• Manual Procedure (No Scan Tool): IPDM E/R Auto-Active Test — To verify the functionality of the IPDM (Intelligent Power Distribution Module). By pressing the driver's door switch 10 times within 10 seconds of turning the ignition on, the IPDM will cycle through its outputs (wipers, lights, A/C clutch). This confirms if the IPDM's internal CPU and relays are working, helping to rule it in or out as a cause without a scan tool.

Wiring & Ground Locations

• IPDM E/R (Intelligent Power Distribution Module Engine Room) — In the engine compartment, behind the battery, under a black plastic cover.. This is the 'smart fuse box' that not only powers many modules but also acts as a CAN gateway. A failure here can cause widespread communication loss and is a very common cause of U1002.
• ABS/VDC Control Unit — Attached to the ABS hydraulic block in the engine compartment, typically on the passenger side.. This is a critical and primary node on the CAN bus. An internal failure of this module is a known cause for bringing the entire network down, triggering U1002 from other modules.
• Main Ground Cable — Connects the negative battery terminal to the chassis/fender apron in the engine bay.. Corrosion at this primary ground point creates high resistance, lowering system voltage and destabilizing all electronic modules, leading to communication codes.
• Engine Block Ground Straps — Multiple straps connecting the engine block to the chassis. One key location on the VK45DE is on the left (driver's) side of the engine.. Provides the ground reference for the ECM and other engine-mounted sensors. A poor connection can cause the ECM to drop off the CAN bus.
• Interior Fuse Box (J/B) — Behind the driver's side kick panel, next to the parking brake pedal.. Contains fuses for many interior modules, including the BCM and Unified Meter/AC Amp. A blown fuse here can take a module offline.

Real Owner Repair Stories

• NICOclub Forums (2006 Infiniti M45) — VDC, SLIP, and ABS lights on. Car would sometimes not start. Received U1000 and U1002 codes.
  ❌ Tried (didn't work) Checking battery, Cleaning ground wires, Replacing the IPDM
  ✅ What actually fixed it The problem was ultimately traced to a faulty ABS actuator control unit. After replacing the ABS actuator with a used unit (part number 47660-EH10D), the codes were cleared and did not return.

OEM Part Supersession History

• 47660-EH10D → Unknown, but multiple compatible part numbers exist for the 2006-2007 model years. — Part revisions and updates by the manufacturer.
  Heads up: Part numbers for the ABS actuator are specific to RWD vs AWD and pre-facelift (2006-2007) vs post-facelift (2008-2010) models. For example, 47660-EH10D, 47660-EH113, and 47660-EH64B are listed for 2006-2007 models. It is critical to match the part number exactly or verify compatibility with the vehicle's VIN.

Model Year Variations Within This Range

• 2008-2010: The M45 received a facelift for the 2008 model year which included significant electronic changes. New features like an optional Hard Drive Navigation system, Lane Departure Prevention (LDP), and an available M45x AWD model were introduced. These changes added more modules to the CAN network (like the LDP control unit and AWD control unit), creating more potential points of failure that would not be present on 2006-2007 models. The interior lighting and gauge cluster illumination also changed from orange to white/violet.