THE GOTECH LIBRARY
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68 resources
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- EVAP concept and evidence
EVAP learning library: understand the system
Learn EVAP basics, compare purge/seal, ESIM and split systems, then connect the concepts to documented cases and unit references.
- EVAP concept and evidence
ESIM explained: test modes and system boundaries
Understand the engine-off and engine-running modes described in GoTech’s ESIM article, with a separate 2014 Dodge Dart refueling case.
- EVAP concept and evidence
Purge/seal EVAP: understand the monitor sequence
Follow vacuum generation, sealing, pressure observation and recovery in the GoTech purge/seal explanation. Keep application-specific thresholds separate.
- EVAP concept and evidence
Split EVAP systems: know which section was tested
Understand the isolation boundary described in GoTech’s split purge/seal article and why one section’s test cannot establish a whole-system result.
- EVAP concept and evidence
What is EVAP? Vapor storage, purge and venting
Learn the roles in a purge/seal EVAP system, then choose a relevant path for repeated nozzle shutoff, P0446 or smoke-test coverage.
- Original article
3.6L GM Misfire
This 2014 Chevy Impala 3.6L had a misfire that was misdiagnosed by multiple shops. Its time to put it through our diagnostic process here at GoTech and get to the root cause of the problem.
- Original article
GM 3.6L Timing Chain Problems: Symptoms, Codes and Diagnosis
Understand the symptoms and code context in GoTech's GM 3.6L timing-chain overview, then continue to diagnosis, labscope testing or replacement.
- Original article
GM 3.6L Timing Chain Diagnosis
Follow GoTech's GM 3.6L timing-chain diagnostic outline, with related-code context and links to VVT operation and the labscope test.
- Original article
GM 3.6L Timing Chain and Reluctor Ring Problems
Read GoTech's original GM 3.6L timing-chain and reluctor ring discussion, with bulletin illustrations and links to diagnosis and replacement guides.
- Diagnostic guide
P0171 & P0174 Lean Codes: First Checks & Repair
Understand P0171/P0174, compare one-bank and both-bank lean conditions, choose useful checks, and follow a GM 1.4L PCV case through repair and recheck.
- Diagnostic guide
P0172 & P0175 Rich Codes: First Checks & Repair
Understand P0172/P0175, compare bank fuel trims, test possible rich-code causes, and follow a Toyota Sienna MAF case through repair and recheck.
- Original article
P0300 Misfire Trouble Code
Learn what a P0300 trouble code means, its symptoms, how to diagnose, and how to clear the diagnostic trouble code
- Original article
What is Variable Valve Timing (VVT)
VVT is a system designed to adjust the timing of an engines valves to optimize performance and lower emissions throughout the engines entire operating range
- Case study
The Ascent case: a change of question
The narrated case begins with a no-crank complaint and a mixed module response list. The list helps frame the question; it does not identify a failed component on its own.
- Original repair guide
How to Diagnose Ford F-150 Wheel Bearing Hub Assembly
Diagnosing a wheel bearing concern can be a daunting task. We have simplified the process to help you quickly and accurately identify a wheel bearing issue on your Ford F-150.
- Original repair guide
GM 2.4L VVT Solenoid Resistance Test with a Multimeter
Follow GoTech's GM 2.4L VVT solenoid resistance test with a multimeter, including setup, source-video moments and related VVT guides.
- Original repair guide
How To Use Your Ohm Meter
Learn how to setup your Ohm meter for testing, the difference between manual adjust and auto ranging, and how to understand the readings.
- Original repair guide
Parasitic Battery Draw Test
A dead battery causing your car to not start is never fun. You recharge the battery or replace it and the vehicle’s alternator is functioning properly, but the car doesn’t start again the next day. The battery is dead again! This is called a parasitic draw or an unintended battery drain.
- EVAP problem finder
EVAP diagnosis: find your next useful check
Start with a P0446 code, repeated fuel-nozzle shutoff or an EVAP leak test. Follow source-backed cases and find the right system explanation.
- EVAP concept and evidence
EVAP canister: storage, flow and restriction clues
Understand vapor storage and the outlet path. See why the Dart refueling symptom led to a remote filter rather than a canister verdict.
- EVAP concept and evidence
Fuel-tank pressure sensor: interpret the evidence
Understand FTP feedback, a fixed reading and the Sierra case. Separate scan-tool data, circuit evidence and a functional recheck.
- EVAP concept and evidence
EVAP smoke testing: know what the test covers
A 2011 Chevrolet Traverse 3.6L smoke-test demonstration: system setup, connection coverage, the excluded purge valve and intermittent-fault limits.
- EVAP concept and evidence
EVAP purge valve: sealing, actuation and flow
Three questions for purge-valve evidence: does it seal, does it respond, and does the expected flow follow? See why a downstream smoke test excludes it.
- EVAP concept and evidence
EVAP vent solenoid: flow, sealing and evidence
Separate an open vent path, a commanded response and sealing performance. Use purge/seal context before interpreting a vent-system code.
- Source-backed case companion
Fuel nozzle keeps clicking off: Dodge Dart case
See how GoTech traced repeated fuel-nozzle shutoff on a 2014 Dodge Dart to its remote EVAP filter, with ESIM context and a refueling recheck.
- Repair hub
GM 3.6L Timing Chain Guides: Diagnosis, Marks & Repair
Find GoTech guides to GM 3.6L timing-chain symptoms, cam/crank signal testing, timing marks, replacement and final mechanical checks.
- Original repair guide
GM 3.6L Timing Chain: Marks & Replacement
GM 3.6L timing-chain replacement with stage 1 and stage 2 timing diagrams, bank-by-bank installation, original video chapters and final checks.
- Original repair guide
How to Test a GM 3.6L Timing Chain
Learn how to test GM 3.L timing chain problems with a labscope - P0008, P0016, P0017 etc
- Repair hub
P0420 Code: Meaning, Causes & Diagnostic Checks
P0420 means catalyst system efficiency below threshold on Bank 1. That tells us what the computer flagged, but not which part to replace. Pick up wherever you are in the diagnosis or repair.
- Repair guide
Exhaust Leak Test for P0420
See how GoTech finds an exhaust leak, then use what you found to choose your next step in a P0420 diagnosis.
- Original repair guide
P0420: Check the Catalyst & Verify Your Repair
Bring your test results, decide what repair they support, or check the work you’ve finished. The filmed Camry diagnosis is here when you need an example.
- Original repair guide
Rear O₂ Sensor Test for P0420
Check whether the rear sensor responds before judging the converter. Watch the GoTech example, then use your result to find the next useful check.
- Original repair guide
P0420 Diagnosis: Find Your Next Check
Bring the findings you already have and identify the next check. Starting checks, test references and the filmed Camry case are here when you need them.
- Repair guide
P0420 Repair Planner: Parts, Replacement & Verification
Know what needs fixing? Check the parts, get the procedure ready and plan how you’ll check the repair. Pick up wherever you are in the job.
- Original repair guide
Replace a 4x4 Vacuum Actuated Hub (IWE)
The integrated wheel end (IWE) on Ford F-150 4x4 is known to make a clicking or ratcheting sound when it begins to fail. This is usually due to a vacuum leak in the actuator. Learn how to diagnose and replace it step by step, including torque specs.
- Original repair guide
How To Replace Driver Side Window Switch Mazda CX-7
Learn how to replace the driver side window switch in a Mazda CX-7 in under 30 min.
- Original repair guide
Knock Sensor Replacement Procedure
Learn how to replace a knock sensor on a 2006-2011 1.6L Kia Rio or Hyundai Accent
- Original repair guide
How to Replace a 2011-2014 Ford F-150 Wheel Bearing Hub Assembly
Step by step instructions, including video, of how to replace your front driverside wheel bearing on a 2011-2014 Ford F-150.
- Original repair guide
How to Replace a 2015-2020 Ford F-150 Cabin Air Filter
Step by step instructions, including video, of how to replace the cabin air filter on a 2015-2020 Ford F-150.
- Original repair guide
GM V8 Oil Pressure Sensor: Location & Replacement
Locate and replace the GM V8 oil pressure sensor with a 2005 Tahoe 5.3L video guide, tool sizes and GM 12677836 vehicle applications.
- Original repair guide
Ford 3.5L Timing Chain Marks & Water Pump Guide
Find Ford 3.5L timing-mark diagrams and colored-link alignment, plus chain and water pump replacement steps demonstrated on a 2010 Fusion.
- Original repair guide
How to Replace a VVT Solenoid on a GM 2.4L
Step by step instructions of how to replace a variable valve timing solenoid on a GM 2.4L
- Original repair guide
Fix Tire Pressure Light
What the tire pressure (TPMS) light means, common causes, and step-by-step ways to fix and reset it—including drive cycles, button resets, and relearn procedures.
- Source-backed case companion
GM P0446: follow the pressure evidence
Follow a 2005 GMC Sierra 5.3L P0446 case: pressure-response clues, circuit checks and the demonstrated retest. Includes source video chapters.
- Original repair guide
GM P0521, P0522 & P0523: Oil Pressure Checks
Separate an oil-pressure sensor signal fault from actual low oil pressure. Review code meanings, screen restrictions and the checks needed before replacement.
- Original repair guide
How to Fix a Ford P1450 EVAP Code
Step by step instructions on how to diagnose and repair a Ford with a P1450 EVAP Code.
- Original repair guide
GM 1.4L P0171: PCV Checks and Repair Guide
Follow GoTech's GM 1.4L P0171 guide through symptoms, PCV checks, repair steps and confirmation, with source-video moments throughout.
- Original repair guide
Fix Chevy Cruze/Aveo/Sonic P0597 & P0598 — Thermostat Heater Circuit (1.8L)
Diagnose and repair Chevy Cruze/Aveo/Sonic 1.8L codes P0597/P0598. Includes thermostat resistance spec (~13–15Ω), control circuit test-light method, replacement steps, tools, torque, and video.
- Learning path
CAN Bus Explained: Communication, Wiring & Diagnosis
Understand automotive CAN bus communication, wiring and diagnostics with GoTech diagrams, real cases and three original videos.
- Lesson
CAN Bus Communication Explained: Networks & Scan Paths
Understand CAN bus communication and scan-tool access. Use a network diagram and GoTech’s Escalade and Acadia cases to identify the branch that matters.
- Lesson
CAN Bus Diagnostics & Troubleshooting: Subaru Ascent Case
Follow a Subaru Ascent no-crank investigation: module responses, diagnostic-port readings, the affected CAN network and what the final findings establish.
- Lesson
CAN Bus Wiring Explained: Topology & Termination
See how CAN bus wiring, junctions and termination change the meaning of a test. Follow GoTech examples before interpreting a module disconnection.
- Learning resource
A short bridge into the lessons
When studying a source reading, record its system/branch, test point and measurement reference, operating state and connection state. Mark any missing condition unknown before comparing it with an expected result.
- Learning resource
Practice evidence-based reasoning
Two GoTech source scenarios for separating an observation from a conclusion and a completed repair.
- Learning path
Wiring Diagram Lessons: Circuits, Voltage & Context
Learn to read wiring diagrams and interpret voltage clues through horn, coil and blower examples, with three GoTech lessons and questions with feedback.
- Lesson
Wiring Diagrams: Missing Context & Voltage
Study connector references, the Taurus coil example and a voltage-reading quiz. Learn what a wiring diagram leaves out, then check your reasoning.
- Lesson
Wiring Diagnosis: Voltage Clues & Blower Controls
Work through the coil quiz and manual versus automatic blower examples. Learn what one voltage reading leaves unknown, with questions and feedback.
- Lesson
Wiring Diagram Basics: Read the Circuit
Learn to follow load, control and ground paths in wiring diagrams using the horn example, timestamped video callouts and three questions with feedback.
- Learning resource
Evidence worksheet
Use this sheet to study a cited case. It does not evaluate your vehicle or prescribe tests.
- Concept reference
Does communication prove a repair?
The source transcript reports TCM communication during temporary substitution. This source packet does not establish ECM replacement, successful engine start, a complete rescan or final vehicle confirmation. Later narration also mentions brake and HVAC communication; these reports still do not establish a completed repair.
- Concept reference
Does 60 ohms mean the network is good?
A resistance reading only has meaning relative to the cited branch/topology, connection state, test point and applicable source expectation. The Ascent lesson changes its interpretation after identifying the diagnostic-port branch; a number alone does not establish whole-network health.
- Concept reference
What does one voltage reading leave unknown?
The third wiring lesson explains that this given reading alone neither settles short-to-power nor verifies operating primary-circuit health. Retain the hypothetical premise and its reference/state.
- Reference resource
Cooling Fan Switch Database
View the entire WVE line of cooling fan switches with specs
- EVAP concept and evidence
EVAP pressure unit converter and reference
Convert Pa, kPa, psi, conventional inches of water and inches of mercury. Preserve the reading’s pressure reference and sign convention.
- Reference resource
Firing Order Database
Identify firing order by vehicle
- Reference resource
Oil Pressure Switch Database
View the entire WVE line of oil pressure switches with specs
- Reference resource
Relay Database
Identify voltage rating, terminal count, amperage, OE numbers and diagrams for relays.
- Reference resource
Starter Solenoid Database
Lookup starter solenoids by part number or through voltage rating and terminal count