Description

Nissan Altima 2007 Diagnostics Manual

You are staring at a 2007 Altima with a check engine light and a code like U1000. The aftermarket scanner says “CAN communication system error,” but it does not tell you which branch line is down. That is where this Nissan Altima 2007 Diagnostics Manual earns its spot on your bench. 202 pages of factory-level CAN diagnosis–not generic theory, not a reprint of some third-party summary. This is the same document the dealer techs used when the car was new, and it still works today.

CAN Communication System Diagnostics – What the Manual Covers

The manual opens with the CAN FUNDAMENTAL section. It walks you through system description, system diagram, and the CAN communication control circuit on page 10. I have seen guys swap an ECM because they guessed a short circuit, but the real fix was a rubbed wire in the DLC branch line. Page 10 gives you the error detection conditions: when U1000 or U1001 is stored and the CAN bus actually reads normal, the manual shows you exactly what to check next. That alone can save half a day of chasing ghosts.

Trouble Diagnosis: When U1000 Appears Even Though CAN Is Normal

Section TROUBLE DIAGNOSIS on page 10 covers this specific pain point. It lists the symptom when an error occurs in the CAN communication system–including open circuits on the TCM branch line, the data link connector branch line, and main line between DLC and ABS actuator. Each example comes with a wiring description and the expected voltage or resistance values. No guesswork.

Branch Line Circuit Procedures – 11 Individual Diagnostic Routines

Once you identify the suspect module, the manual gives you a dedicated diagnosis procedure for each branch line: ECM branch line circuit (page 37), A-BAG branch line circuit, BCM branch line circuit, DLC branch line circuit, M&A branch line circuit, STRG branch line circuit, ABS branch line circuit, TCM branch line circuit, IPDM-E branch line circuit, and the main line between DLC and ABS or TCM. Each procedure includes a step-by-step check of continuity, short to ground, and short to power. You need a digital multimeter and a CONSULT-III interface–both are called out in the required tool list. I do not start a CAN diagnosis without confirming the branch line resistance specs from this manual.

Precaution for SRS – Why You Follow the Manual

The supplement restraint system section is not filler. Page 22 lists the specific precautions for the air bag and seat belt pre-tensioner. If you probe the wrong pin on the A-BAG control unit without disabling the system first, you can deploy a bag. The manual tells you the mandatory discharge time and the correct harness repair procedure. Skip that step and you are looking at a liability problem, not a repair.

Interview Sheet and Workflow – Real-World Use Case

Inside the BASIC INSPECTION section there is an interview sheet (page 24) that helps you capture the customer’s complaint systematically. For a home garage guy who does not talk to the owner every day, writing down when the problem occurs (hot engine, cold start, after rain) changes how you read the CAN communication signal chart. The chart on page 25 shows what each control unit is sending on the bus. Pair that with the Automotive Industry Overview of controller area networks, and you can pinpoint a missing message in minutes.

Source Validity – Original OEM Print, Not Aftermarket

This is a factory Nissan Diagnostics Manual, published in 2007, drawing from the original Lan System service information. Aftermarket CAN books often consolidate multiple years into one vague chart, which leads to wrong pinouts. Here, the CAN System Specification Chart lists vehicle equipment identification for the 2007 Altima only. If you need the full service procedures to complement this manual, grab the Nissan Altima 2007 Service Manual and the Nissan Altima 2007 Transaxle and Transmission Service Manual. For the air bag control module specifically, see Nissan Altima SRS Airbag Control System Service Manual.

FAQ – Two Questions

Does this manual include wiring diagrams?

Yes. Page 30 has the full wiring diagram for the CAN system, and each branch line circuit includes its own schematic in the diagnosis procedure.

Can I use this for a 2008 or 2009 Altima?

No. This Diagnostics Manual is specific to the 2007 model year. The CAN system type changed in 2008 with the introduction of the CVT and different BCM communication protocols. Using the 2007 chart on a 2008 car will give you incorrect termination resistances and wrong signal charts. Buy the corresponding year manual for accurate data.

I do not carry a 2007 Altima into my bay without this PDF loaded on the tablet. The factory procedure for the main line between DLC and ABS circuit, the CAN diagnostic support monitor items, and the condition of error detection are all things that a generic OBD scanner will not show you. If you work on these cars, you need the original source. Access the Factory Manual.