Fuel-pump replacement on a 2005–2007 Chevrolet TrailBlazer 4.2L inline-six starts with confirming the cause of long cranking, a crank-no-start, loss of power or an erratic fuel gauge. A stored P0463 fuel-level sensor circuit high-voltage code calls for sender-circuit diagnosis; it does not prove the pump motor has failed. This guide covers product fitment, tank removal, a new module and seal, and the checks needed before driving.
Which TrailBlazer does this guide cover?
The written procedure uses a 2007 Chevrolet TrailBlazer LT, 4.2L inline-six gasoline engine, four-door standard body, 4WD and automatic transmission. The featured module also lists other engines and related vehicles below; their fuel-tank access and service details must be checked separately.
Planning allowances assume a confirmed pump fault, usable original fittings and access to an equipped hoist bay. Diagnosis, corrosion repairs, facility charges and equipment purchases are extra.
Featured replacement fuel-pump module
A-Premium FP0173, ASIN B07B8JHBM4, is a 12-volt in-tank gasoline fuel-pump module. The selected listing supplies one assembly with a pressure sensor, fuel-level sending unit, strainer and tank seal. The manufacturer also confirms the float. Listed interchange references include 19153374, 19178476 and 21998332.
The selected photograph shows one complete module and a separate green tank seal. A new retaining lock ring is not confirmed in the package. Before dismantling the vehicle, compare the delivered flange, pipes, connectors, sensor, float and seal with the correct parts for your VIN. Resolve differences with the supplier before opening the tank.
View the TrailBlazer fuel-pump module
Product compatibility: exact years and engines
These are the module’s listed applications, not one shared installation procedure. The steps below apply to the stated standard-body 4.2L TrailBlazer. All rows are gasoline applications.
| Vehicle | Model years | Engine | Body style |
|---|---|---|---|
| Chevrolet TrailBlazer | 2005–2007 | 4.2L I6 | Sport Utility |
| Chevrolet TrailBlazer | 2006–2007 | 5.3L V8 | Sport Utility |
| Chevrolet TrailBlazer | 2006–2007 | 6.0L V8 | Sport Utility |
| Chevrolet TrailBlazer EXT | 2006 | 5.3L V8 | Sport Utility |
| GMC Envoy | 2005–2007 | 4.2L I6 | Sport Utility |
| GMC Envoy | 2005–2007 | 5.3L V8 | Sport Utility |
| GMC Envoy XL | 2005–2006 | 5.3L V8 | Sport Utility |
| GMC Envoy XUV | 2005 | 5.3L V8 | Sport Utility |
| Buick Rainier | 2005–2007 | 4.2L I6 | Sport Utility |
| Buick Rainier | 2005–2007 | 5.3L V8 | Sport Utility |
| Isuzu Ascender | 2005–2007 | 4.2L I6 | Sport Utility |
| Isuzu Ascender | 2005–2006 | 5.3L V8 | Sport Utility |
| Saab 9-7x | 2005–2007 | 4.2L I6 | Sport Utility |
| Saab 9-7x | 2005–2007 | 5.3L V8 | Sport Utility |
| Chevrolet SSR | 2005–2006 | 6.0L V8 | Convertible |
Watch the differences: standard TrailBlazer V8 rows begin in 2006; TrailBlazer EXT is 2006 5.3L only; Envoy XL and XUV rows also have narrower engine/year coverage. The listing does not specify drivetrain, transmission or tank-capacity restrictions. Confirm the VIN, original reference and actual fuel/electrical connections rather than assuming a model name alone establishes fit.
Fuel and lifting safety
This walkthrough requires an equipped hoist bay and a trained lift operator. The selected tall tank jack starts at 35 inches before its cradle; it is not a driveway jack-stand setup. Have an assistant guide the drained tank. If these facilities are unavailable, arrange professional installation.
Work with a cool engine/exhaust, ventilation, splash goggles, gasoline-compatible gloves and an accessible Class B-rated extinguisher. Remove flame, smoking, spark and hot-work sources. Use gasoline-approved transfer/storage equipment and its bonding/grounding provisions; promptly contain spills and fuel-wet cloths.
Stop for a leaking or damaged tank, badly corroded mounting flange, unsafe straps/frame, broken pipe nipples or heat-damaged connectors. Correct those faults before assembly or activation. The supported access is tank removal from underneath; do not cut a floor opening.
Separate pump, level-sender and electrical faults
- Have codes and useful diagnostic data recorded before disconnecting the battery. P0463 means fuel-level sensor circuit high voltage; it calls for level-circuit diagnosis and does not prove the pump motor has failed.
- For hard starting or a crank-no-start, have a technician confirm fuel quantity, battery performance, pump electrical supply and actual fuel delivery. A noise from the tank does not establish correct pressure, and silence can have an electrical cause.
- Inspect accessible connectors and lines for heat damage, corrosion, leaks or loose retainers. A damaged connection requires a proper repair, not simply a new pump plugged into it.
The 2007 4.2L service specification is 345–395 kPa (50–57 psi), ignition on and engine off. Have a technician use the correct gauge, connection and pump operating conditions; do not substitute a V8 pressure range. This returnless system also requires checking the regulator/check-valve and electrical causes when interpreting a low reading.
A fuel-level complaint and a delivery complaint may need different tests. Confirm the fault before choosing a complete module replacement, and have the relevant measurement repeated after repair.
Tools, parts and supplies
The list assumes an existing equipped hoist bay. Match each drive, capacity and actual fastener head; the filler clamp needs the low-range torque wrench. Use the supplied correct seal once, and buy a separate ring only when inspection requires it. Existing suitable tools, clean wipes and a small amount of clean engine oil are sufficient.
| Tool or Supply | Exact Product | Product Link | Purpose and Selection Check |
|---|---|---|---|
| Installed vehicle hoist and equipped service bay | BendPak 10AP two-post vehicle lift; existing suitable installed equivalent acceptable — 10AP / 5175304 | View exact hoist requirements | Existing installed hoist: 10,000 lb total, 2,500 lb per arm. A trained operator must verify factory frame contact, balance, clearance, locks and required auxiliary support/restraints for this under-hoist route. |
| Under-hoist tank jack | Sunex 1000 lb telescopic transmission jack — 7793B | View under-hoist tank jack | 1,000 lb capacity; minimum saddle height 35 inches before the adapter. Use only beneath a properly raised hoist, with the 7706 cradle securely mounted and an assistant guiding the drained tank. |
| Strapped fuel-tank cradle | Sunex fuel tank adapter — 7706 | View matching strapped tank cradle | For EMPTY tanks up to 40 gallons. Fit to the 7793B using the supplied mounting system; adjust padded supports, apply both straps and follow grounding instructions before removing vehicle straps. |
| Metric sockets, ratchet and extensions | TEKTON 3/8-inch drive 6-point socket and ratchet set — SKT15201 | View metric socket set | 3/8-inch drive, 6–24 mm six-point sockets with ratchet/extensions. Match the actual shield, brace, strap, battery and filler-clamp heads; TRQ specifies a 7 mm filler-clamp head. |
| Low-range torque wrench | EPAuto 1/4-inch drive click torque wrench, 20–200 in-lb | View low-range torque wrench | 1/4-inch drive; 20–200 in-lb (2.26–22.6 N·m) covers the 2.5 N·m filler clamp and 15 N·m battery fastener. Use the adapter below and read the inch-pound scale correctly. |
| Torque-wrench drive adapter | TEKTON 1/4-inch female to 3/8-inch male drive adapter — SHA04101 | View correct drive adapter | 1/4-inch female input accepts the low-range wrench; 3/8-inch male output accepts the socket set. This fully seated coaxial connection changes drive size without an offset lever arm. |
| Tank, shield and brace torque wrench | EPAuto 3/8-inch drive click torque wrench, 10–80 ft-lb | View medium-range torque wrench | 3/8-inch drive; 10–80 ft-lb (13.6–108.5 N·m) covers 32 N·m straps/shield and the 50 N·m brace. Selected sockets fit directly; use the low-range wrench for the filler clamp. |
| Small flat-blade hand tool | Wiha precision slotted screwdriver — 26035 | View small flat-blade tool | 3.5 mm tip, 60 mm blade for the OEM towel-shielded rail-valve relief method and applicable connector locks. Work slowly on a cold, switched-off engine; never hammer the module ring. |
| Fuel-module lock-ring wrench | GM / Kent-Moore fuel-sender lock-ring wrench — J-45722; current GM catalog GM-45722 | View exact J-45722 ring wrench | J-45722 engages the OEM retaining ring and takes the 1/2-inch breaker bar below. Secure the tank against rotation, fully engage the lugs and use manual force; no impact or hammering. |
| Lock-ring breaker bar | TEKTON 1/2-inch-drive 24-inch breaker bar — SBH00224 | View 24-inch breaker bar | 1/2-inch drive, 24-inch length connects directly to J-45722. Use controlled manual leverage with the tank secured; do not add a pipe extension or substitute an impact tool. |
| Retaining-ring flatness gauge | GEARWRENCH 32-blade SAE/metric feeler gauge — 161D | View correct feeler-gauge set | Includes the 0.016-inch (0.406 mm) blade for the OEM 0.41 mm limit. Check all seven positions on a clean, known-flat surface; replace damaged or excessively warped rings. |
| Conditional replacement retaining ring | GM Genuine Parts fuel-tank lock ring — 10325852 / ACDelco TR26 | View VIN-matched replacement ring | Needed only if the original ring is damaged or fails the seven-point flatness check. Confirm VIN/tank fit; a separate retaining ring is not promised with the featured pump. |
| New module-to-tank seal | New tank seal supplied with the featured A-Premium module — FP0173 supplied seal | Check featured module and included seal | Use the correct new seal supplied with FP0173; check its profile and fit before installation. Keep the seal groove unlubricated. If missing or mismatched, resolve the exact seal with the supplier. |
| Clean temporary fuel-line caps | Lisle Master Line Stopper Set — 67000 | View fuel-line cap and stopper set | Clean stoppers span 1/8–1/2 inch; caps are 5/8–3/4 inch. Match the actual depressurized connections without forcing. Keep dirt out and remove every temporary cap before reconnecting. |
| Splash eye protection | 3M chemical-splash goggles — 91252H1-DC-10 | View splash goggles | Wear fitted splash goggles before relieving pressure, opening fuel joints or cleaning with air. Check the lens, strap and seal, and shield against fuel and displaced dirt. |
| Chemical hand protection | Ansell AlphaTec Solvex nitrile chemical gloves; choose a fitted size — 37-175 | View exact Ansell glove and sizes | Choose a fitted 37-175 nitrile gauntlet and check the actual gasoline blend against the chemical guide. Avoid sustained contact and replace contaminated or damaged gloves; test results are not safe wearing time. |
| Accessible Class B fire extinguisher | First Alert rechargeable home/workshop fire extinguisher — HOME2PRO | View Class B-rated extinguisher | UL 2-A:10-B:C includes flammable-liquid coverage. Check ready condition and keep accessible by a clear exit. Remove ignition sources and provide ventilation before opening the gasoline system. |
| Small-spill absorbent | New Pig Universal Light-Weight Absorbent Mat Roll, 15 inches × 50 feet — 25201 | View gasoline-compatible absorbent roll | Universal automotive-fluid mat explicitly covers gasoline. Place sections in the catch area for small drips; put saturated material into the self-closing solid-waste can rather than leave it near ignition sources. |
| Temporary module drip tray | FloTool galvanized metal drip tray, 25 × 36 inches — 11430 | View metal module drip tray | 25 × 36-inch galvanized steel tray catches residual fuel from connections and the removed module. Keep stable, prevent overflow and transfer liquid to approved gasoline containment; it is not storage. |
| Gasoline draining and temporary service storage | JohnDow PRO30 manual fuel caddy — FC-P30-UL, red gasoline configuration | View complete manual gasoline caddy | 30-gallon manual gasoline caddy with rated hose and grounding equipment. Confirm sufficient free capacity, bond/ground correctly and drain through the disconnected filler hose. Use only as permitted temporary service storage. |
| Residual-gasoline safety can | Eagle five-gallon Type I red gasoline safety can with funnel — UI50FS | View residual-gasoline safety can | Five-gallon red Type I gasoline can with closing lid and flame arrester. Use for residual liquid when needed, keeping free capacity; bulk tank draining uses the caddy and wet cloths stay separate. |
| Fuel-wet cloth waste can | Justrite foot-operated oily-waste can, 6 gallons — 09100 | View self-closing cloth-waste can | Six-gallon steel can for contaminated cloths and absorbent sections. Keep the self-closing cover shut between deposits. This holds solid waste; captured liquid gasoline belongs in approved fuel containment. |
| Clean lint-free wipes | Texwipe AlphaWipe dry polyester cleanroom wipers, 9 × 9 inches — TX1009 | View exact lint-free wipe reference | Use fresh, dry lint-free wipes without wax, polish or presaturation. Keep fibers out of fuel connections and move wet wipes promptly to the waste can. Existing suitable clean cloths suffice. |
| Clean engine oil for quick connections | Shell Rotella T4 Triple Protection 15W-40 diesel engine oil, 1 gallon | View clean engine-oil reference | Use only a few drops of clean engine oil on the cleaned male quick-connector ends. Existing suitable clean oil suffices. Keep oil and grease out of the module-seal groove. |
| Safety blowgun with the bay’s regulated air supply | Milton safety blowgun with 4-inch extension — 131 | View exact safety blowgun | Use the bay’s clean regulated air and compatible hose with the 1/4-inch NPT inlet. Keep safety vents unobstructed and wear goggles; clean closed fittings only, never open fuel ports. |
DIY versus professional repair cost
These U.S. dollar figures are planning ranges, not current listing prices or shop quotes. They assume existing common hand tools and safety equipment; obtain a written diagnosis and itemized estimate.
| Expense | Planning range | What to allow for |
|---|---|---|
| Replacement module | $90–180 | One correctly matched aftermarket assembly; inspect its supplied seal |
| Consumables and conditional hardware | $40–100 | Absorbents and needed retaining/sealing parts; do not automatically buy a second supplied seal |
| DIY parts and supplies | $130–280 | Excludes tools, fuel contamination and damaged tank/line repairs |
| Equipment and facility | Obtain a separate quote | Existing equipped hoist bay assumed; buying a lift, fuel caddy and tank-support equipment is outside the DIY parts budget |
| Professional labor allowance | $360–720 | Illustrative 3–4 billed hours at $120–180/hour |
| Professional installed allowance | $530–1,110 | Labor plus $150–350 parts and $20–40 supplies; diagnosis, tax and additional repairs are extra |
Rust-damaged retaining parts, connectors or fuel lines can change the job substantially. A sender, wiring or emissions-system fault may require a different repair; replacing the whole module is not a substitute for diagnosis.
Step-by-step replacement: 2007 TrailBlazer 4.2L 4WD
The sequence follows GM’s 2007 4.2L tank procedure and module replacement instructions. It retains the original tank and its serviceable plumbing. Confirm different or previously modified hardware before applying these specifications.
1. Confirm the part and isolate electrical power
Confirm the VIN, body, original module reference and delivered assembly before opening the system. Secure cargo, select Park and set the parking brake. Record useful diagnostic information first. With ignition in LOCK and all loads off, disconnect and isolate the negative battery cable so it cannot spring back onto its terminal.
2. Relieve tank and fuel-line pressure
Slowly loosen the fuel cap to release tank vapor pressure. Locate the fuel-rail service/test port and remove its cap. Completely shield the port with an absorbent towel, then carefully depress its valve with the small flat-blade tool, allowing retained fuel pressure to discharge into the towel. Keep your face away and contain all fuel.
When pressure subsides, replace the service-port cap, place wet cloths in the covered waste can and retighten the fuel cap until draining. This factory pressure-relief alternative works even when the engine cannot start. Cap removal alone does not relieve the fuel line. If the valve cannot be safely accessed and contained, have a technician use the specified gauge method before proceeding.
3. Raise the vehicle at the approved frame contacts
Have the operator verify lift capacity, individual arm loading, balance and clearance. Use the factory frame contact areas; pads must sit on flat areas at least 50 mm (2 inches) from the frame radius, clear of pipes and wiring. Follow the lift/OEM precautions for component removal, including required auxiliary supports or restraints, and engage the mechanical locks before working underneath.
4. Remove the covers and drain the tank
Support and remove the frame brace and, if fitted, the tank shield; keep their hardware organized. Leave the tank straps installed. Loosen the filler-hose clamp and carefully separate the hose from the tank neck. Remove the fuel cap for draining.
Use the gasoline-rated manual caddy to remove as much fuel as possible through the tank’s filler connection. Verify free capacity and follow its bonding/grounding instructions. The selected cradle is rated for empty tanks: drain before transferring the load to it. Keep collected fuel in approved closed containment; do not use a household vacuum, drill pump or mouth siphon.
5. Disconnect accessible fuel and EVAP connections
Record the original routing. Clean each closed fitting with the bay’s regulated safety air and clean wipes, keeping the air source away from fuel vapors. Shield joints against residual fuel while opening them; do not blow into an open tank or pipe.
Disconnect the three rear EVAP paths—canister fresh-air, canister-solenoid and purge connections—plus the filler recirculation hose and any remaining filler connection. Disconnect the front fuel-feed and EVAP pipes. Identify each plastic retainer before release: use its opposed squeeze tabs/ring, sliding Q-style retainer or push-down TI tab only as applicable. Do not pry against a molded nipple or kink nylon lines. Fit clean, compatible temporary caps to openings.
6. Support, unstrap and lower the tank carefully
Center the drained tank on the padded 7706 cradle, correctly mounted to the 7793B jack. Apply both cradle straps and follow its grounding instructions. With the support taking the load, remove the two vehicle strap bolts and disengage the tank straps without bending them.
Lower only enough to access the vent-valve, fuel-tank-pressure sensor and pump/sender electrical connectors. Release any secondary connector-position locks before the main latches; pull the housings, not wires. Check that every pipe, clip and harness is free, then lower the tank level with your assistant. Never let it hang from a hose, wire or one strap.
7. Free the module pipes and remove the retaining ring
Clean the closed tank top. Disconnect the module’s fuel-feed and EVAP pipes, releasing only necessary reusable clips. Preserve the routing ties and remaining plumbing. This returnless system has no engine fuel-return pipe at the module; the top pressure sensor serves EVAP monitoring.
Note the module’s locator/orientation and secure the tank against rotation. Fully engage J-45722 and its long manual breaker bar, turning the ring counterclockwise. Control the module’s spring pressure as the ring releases. Lift by the module body, guiding the float and strainer through the opening, and catch residual fuel. Discard the old tank seal.
8. Inspect the flange and ring
Check the sealing seat, retaining tabs and tank interior for damage or contamination. On a clean, known-flat surface, measure the removed ring at all seven inspection positions with the feeler gauge. GM permits reuse of an undamaged ring with warpage less than 0.41 mm (0.016 inch). Replace a damaged, excessively warped or uncertain ring; do not force it onto defective tank tabs.
9. Fit the new seal and lock the module
Seat the correct new supplied seal dry in the clean groove, without twisting it. Keep oil, grease, silicone and sealant out of this groove. Check that the strainer sits horizontally and the float moves freely. Guide the module into the tank, align its locating features and compress it squarely without displacing the seal or trapping the float.
Install the sound ring with its correct face upward. Use J-45722 manually clockwise until every retaining tab is fully captured in the locked position. No numerical ring torque is specified. Do not substitute hammering or an impact tool.
10. Reconnect and secure the tank
Apply a few drops of clean engine oil to the cleaned male quick-connector ends only. Reconnect the top feed and EVAP pipes until they engage; gently pull on both sides to confirm retention. Restore the reusable clips and check the preserved routing ties.
Raise the strapped tank enough to restore all three electrical connectors, including their secondary locks. Route wiring clear, then raise the tank fully without trapping hoses. Refit the straight straps, start their bolts by hand and tighten to 32 N·m (24 ft-lb). Do not use the bolts to haul a misaligned tank into place.
Remove every temporary cap and restore the front feed/EVAP, rear EVAP and filler recirculation connections. Confirm each quick connector’s positive engagement and pull-check it. Seat the filler hose fully at its original stop, correctly position its clamp and tighten to 2.5 N·m (22 in-lb). Check all line clearances and wiring retainers before removing the tank support.
11. Refill, prime and inspect before installing the shield
With the tank fully retained, remove its support and lower the vehicle. Refill with clean gasoline using approved handling equipment, adding enough to cover the pickup, and secure the fuel cap. With ignition and loads off, reconnect the original negative cable and tighten its bolt to 15 N·m (11 ft-lb).
Raise the vehicle again on the locked hoist for inspection, with everyone clear of moving parts. Have an assistant switch ignition ON, engine OFF, for 10 seconds; OFF for 10 seconds; then ON again, engine OFF. This is a key sequence, not a claim that the pump runs continuously for ten seconds.
Inspect every opened connection, the module flange as visible, and the tank/filler area for fuel wetness or abnormal odor. If a leak appears, switch OFF, isolate the negative cable and relieve retained pressure before reopening a connection. Correct the fault and repeat the check. Keep the shield off until these checks pass.
12. Refit protection and check operation
Switch ignition off. Refit the optional shield, tightening its bolts/nut to 32 N·m (24 ft-lb), and the frame brace to 50 N·m (37 ft-lb). Lower the vehicle and start normally with everyone clear. Check stable idle, no fuel wetness or odor, and a plausible gauge reading for the amount added.
Recheck after shutdown. Take a short test drive only after those checks pass, then inspect again. A persistent no-start, incorrect gauge or warning light needs diagnosis rather than prolonged cranking. Have the original fault checked after repair; a pressure-side leak check alone does not establish that every EVAP monitor will pass.
Repair video: 2007 TrailBlazer 4.2L
TRQ’s video identifies a 2007 TrailBlazer LT 4.2L, 4WD, automatic; its broader 2002–2009 title and tool/priming choices do not expand the featured part’s fitment or replace this guide’s written factory procedure and specifications.
Common mistakes to avoid
- Ordering by model name alone, particularly confusing the standard body with EXT or assuming every V8 year is covered.
- Lowering a fuel-filled tank, using an unsecured support, bending tank straps or stretching a hidden connector.
- Hammering the retaining ring, reusing the old tank seal or applying oil/sealant in the tank-seal groove.
- Mixing up the fuel-feed and EVAP pipes, overlooking the third electrical connector or skipping the retention check after a fitting clicks.
- Confusing inch-pounds with foot-pounds on the filler clamp, covering connections before the leak check or using prolonged cranking to prime.
Frequently asked questions
Does this module fit every 2005–2007 TrailBlazer?
Check the engine and body. The listed standard-body 4.2L covers 2005–2007, while 5.3L/6.0L coverage begins in 2006. The EXT row is 2006 5.3L only. Confirm the VIN and original module.
Is a new tank seal included?
The selected listing includes a seal and its photo shows one green ring. Inspect the delivered seal for the correct size and condition. Use a new correct seal for the opened tank; do not stack it over the old one.
Will replacing the module fix an inaccurate fuel gauge?
The module includes a level sender and float, but a wiring or gauge fault can remain. Diagnose the level circuit before deciding which part needs replacement.
Can I use the same steps for an Envoy XL, TrailBlazer EXT or SSR?
Product compatibility does not establish identical access or tank hardware. Use the service procedure for that exact body and engine. This walkthrough is for the stated standard-body 2007 TrailBlazer 4.2L.
What if the new module’s connector or pipe layout differs?
Stop and confirm the supplied part using the VIN and original reference. Do not alter the tank, force connectors or splice an unfamiliar harness to make an unconfirmed module fit.
Sources and further reading
Vehicle specifications come from the stated 2007 4WD 4.2L service information. The product catalog supplies the separate year/engine application table; it does not establish a shared procedure for every vehicle listed.
- A-Premium FP0173 specifications and exact vehicle applications
- GM service information: 2007 TrailBlazer 4WD 4.2L tank removal and installation
- GM service information: 2007 TrailBlazer 4WD 4.2L module and lock-ring procedure
- GM service information: 4.2L pressure relief without a gauge
- GM service information: plastic-collar quick connections
- GM service information: fuel-tank draining
- GM service information: lifting contacts and precautions
- GM service information: original negative battery cable
- GM service information: standard-body shield and frame-brace installation
- GM service information: 2007 4.2L key-on, engine-off pressure specification
- GM service information: 4.2L returnless fuel-system diagnosis
- GM service information: P0463 fuel-level circuit diagnosis
- GM catalog: 2007 TrailBlazer LT 4.2L retaining hardware
- TRQ / 1A Auto: the 2007 TrailBlazer repair-video application