U1001 On Nissan vehicles, U1001 is a CAN network communication code, stored when control units cannot communicate over the CAN lines

Nissan CAN communication circuit code

U1001 in short

On Nissan vehicles, U1001 is a CAN communication code: control units cannot talk over the CAN lines. Nissan says to diagnose these communication codes first. A 2017 Armada bulletin calls for a new IPDM, and owners report stalls and a charging system fault. Have it checked soon.

Nissan control units share data over a CAN network. U1001 and its siblings U1000, U1002 and U1010 mean communication over that network failed, and Nissan service information says a module reporting U1000 is typically fine and the error is elsewhere on the network. This page speaks only for Nissan.

A 2017 Armada bulletin applies when P0090 is set with U1000 and/or U1001 in other control units and tells technicians to replace the IPDM (the power distribution module). Owners report U1001 with a bad charging system and blown fuse on a 2004 Sentra, with U1000 and ECM and ABS suspicion on a 2006 Armada, and with a stall on a 2007 Pathfinder.

Nissan lists the same code family for Infiniti under its own bulletins, but this page covers Nissan only.

Pick your make

U1001 is a manufacturer-specific code: its meaning depends on who built the car.

Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.

Most likely causes

  1. CAN network wiring or another unit disturbing the bus

    Supported by vehicle data
    Why it ranks here
    Nissan NTB10066A tells technicians to diagnose communication codes first and use the CAN diagram or CAN diag support monitor to find where the error is.
    What would change this
    Rises if several units report U1000 or U1001. Falls if the CAN test shows the bus is fine.

  2. IPDM (intelligent power distribution module) fault

    Supported by vehicle data
    Why it ranks here
    Nissan NTB17-020 replaces the IPDM on a 2017 Armada with P0090 and U1000 or U1001, and a 2002 Altima dealer wanted to replace the IPDM with only U1000 and U1001 stored.
    What would change this
    Rises on the 2017 Armada with P0090. Falls on other vehicles or if the IPDM tests fine.

  3. Weak battery or charging system fault

    Supported by vehicle data
    Why it ranks here
    A 2004 Sentra stored U1001 after an alternator and fuse problem, and shops then pointed to the battery and the charging system.
    What would change this
    Rises if the battery or alternator tests poor. Falls if voltage is steady.

  4. ECM or ABS assembly fault

    Possible — needs testing
    Why it ranks here
    A 2006 Armada dealer advisor said U1000 and U1001 hard codes with the ECM and ABS assembly might mean replacing those systems, which the complaint does not confirm.
    What would change this
    Rises if those units fail testing after the bus checks good. Falls if they respond.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all control units for codes and note whether U1000, P0090 or charging codes are stored with U1001.

    Low riskTool: scan tool that reads all control units

  2. Test the battery and charging system, then have the CAN lines checked using the Nissan CAN diagram or the CAN diag support monitor.

    Use cautionTool: multimeter and scan tool

    Warning:Disconnect the battery before touching module connectors. Do not probe airbag circuits.

Symptoms

  • Check engine light
  • Engine stalls or will not restart Gets more serious: stop and have it checked.
  • Gauges or lights act up after electrical repairs
  • Loss of power Gets more serious: stop and have it checked.

How to fix

  1. Check that the battery is healthy and the terminals are clean and tight, then clear the codes and see if U1001 returns.

On your vehicle

Nissan

  • NTB17-020Status unverified

    MIL on with P0090 and U1000 and/or U1001 stored

    2017armada · issued · NHTSA 10119192

    Replace the IPDM when P0090 is set with those U-codes in other units. Only the NHTSA summary was read.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • NTB10066AStatus unverified

    Service information on communication codes U1000, U1001, U1002 and U1010

    2005–2015350z, 370z, altima, armada, cube, frontier · issued · NHTSA 10192394

    Diagnose communication codes first using the CAN diagram or CAN diag support monitor. Only the NHTSA summary was read.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • U1000Manufacturer code: on Nissan and Infiniti a module saw an error on the CAN network; on older GM vehicles it is a Class 2 serial data fault

    Same system Supported by vehicle data

    Nissan treats U1000 and U1001 together as communication codes to diagnose first.

  • P0090Fuel pressure regulator control circuit fault

    Shares causes Supported by vehicle data

    Nissan NTB17-020 applies only when P0090 is set with U1000 and/or U1001.

All Module network (CAN bus) communication codes

U1001 questions

Does U1001 mean the same on other makes?

Not necessarily. This page covers Nissan only; we have not sourced meanings for other makes.

Sources and review

  1. Nissan NTB17-020 (NHTSA 10119192): 2017 Armada MIL on with P0090 and U1000 and/or U1001 — NHTSA (manufacturer communication)
  2. NHTSA complaint ODI 10583698: 2007 Nissan Pathfinder — NHTSA (owner complaint)
  3. NHTSA complaint ODI 10905168: 2004 Nissan Sentra — NHTSA (owner complaint)
  4. Nissan NTB10066A (NHTSA 10192394): service information on communication codes U1000, U1001, U1002 and U1010 — NHTSA (manufacturer communication)
  5. NHTSA complaint ODI 10241774: 2002 Nissan Altima — NHTSA (owner complaint)
  6. NHTSA complaint ODI 10915486: 2006 Nissan Armada — NHTSA (owner complaint)
Last reviewed
Written by
Saurabh K.
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