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2003 Isuzu Ascender 4WD

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 2003 Ascender 4WD.

The 2003 Isuzu Ascender 4WD is a mid‑sized all‑wheel‑drive SUV that, for that model year, accumulated 35 owner complaints with exterior lighting cited as the primary issue, and it was subject to five recalls, positioning it toward the lower end of the reliability spectrum for the Ascender line.

Model year20052003

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

Lug nut torque100 ft-lbsOEM · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

From the factory this vehicle uses a BCI 78 · 600 CCA battery, OE oil filter 8889842150. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

Battery groupBCI 78 · 600 CCAOEM · verified
Tire sizeP245-65R17OEM · verified
Wheel / rim7-J inOEM · verified

OE service part numbers OEM · verified

Engine oil filter8889842150 alt 8890173420
Engine air filter8192397130
Fuel filter8889830680
Spark plug2901230720 alt 8126816630
Front wiper blades8152143460
Thermostat8125611550 alt 8125712610

Full specifications

Engine, drivetrain, dimensions and economy.

Dimensions & weight NHTSA vPIC

Overall length207.5 in
Overall width74.8 in
Overall height77.2 in
Wheelbase129.1 in
Curb weight4837 lb
Track (front / rear)62.2 / 62.2 in
Weight distribution (front / rear)54/46

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine SYNTHETIC · 75W-90 · GL-5 in the differential. Torque lug nuts to 100 ft-lbs, the oil drain plug to 18.0 ft-lbs. The firing order is 1-5-3-6-2-4. Note the cylinder-head bolts finish on a torque angle (torque-to-yield) — they stretch permanently and should be replaced, not reused, during any head service.

Lubricants & capacities

Differential Gear OilSYNTHETIC · 75W-90 · GL-5
Differential Gear Oil Capacity4.3 Pints
Engine CoolantDEX-COOL OR EQUIVALENT
Power Steering FluidGM PART NO. 89021184 OR EQUIVALENT
Transfer Case FluidGM PART NO. 12378508
Transfer Case Fluid Capacity3.8 Pints

Engine torques

Camshaft Bearing/Carrier Cap Bolts or Studs9 ft-lbs
Intake Manifold to Engine Bolts7.4 ft-lbs
Intake Manifold to Engine Bolts7.4 ft-lbs
Engine Oil Pan Drain Plug19.0 ft-lbs
Engine Oil Pan Drain Plug18.0 ft-lbs
Oil Pump to Cylinder BLock Bolts/Studs7 ft-lbs

Chassis torques

Lug Nuts100 ft-lbs
Front Wheel Hub103 ft-lbs

Ignition

Cylinder Firing Order1-5-3-6-2-4
Spark Plug Gap0.040 in
Spark Plug Torque13.0 ft-lbs

Battery & A/C

RefrigerantR134a
Oil GroupPAG
Oil Type46
Oil Capacity5.00 oz
Standard BCI Group Number78
Standard BCI Cranking Performance600 cca
Standard BCI Group Number78
Standard BCI Cranking Performance600 cca

Service checks

Pressure Test15 psi
Radiator Cap Pressure Relief15 psi
Thermostat Opening Temperature188-206 °F
Pressure Test15 psi
Radiator Cap Pressure Relief15 psi
Thermostat Opening Temperature188-206 °F
Fuel Pump Pressure Minimum50.0 psi
Fuel Pump Pressure Maximum57.0 psi

Brakes

Torque Caliper to Bracket85 ft-lbs / 23 ft-lbs
Torque to Knuckle133 ft-lbs / 89 ft-lbs
Minimum Pad Thickness0.039 in
Minimum Shoe Thickness0.039 in
Rotor Max Parallel Variation0.0001 in
Rotor Runout Limit0.002 in
Rotor Nominal Thickness From1.142 in / 0.787 in
Rotor Nominal Thickness To1.142 in / 0.787 in

Multi-step torque procedures OEM · verified

Connecting Rod (Large End) Bearings — tightening sequence 1 stages
118 ft. lbs., Step 2: 11018 ft. lbs
Cylinder Head — tightening sequence 5 stages
1M11 bolts22 ft. lbs
2M11 bolts90 degrees
3M11 bolts 1-890 degrees
4M11 bolts 9 and 1050 degrees
522
Engine Flywheel Bolts — tightening sequence 1 stages
118 ft. lbs., Step 2: 5018 ft. lbs
Exhaust Manifold to Cylinder Head Bolts — tightening sequence 1 stages
115 ft. lbs, Step 2: 15 ft. lbs., Step 3: 1515 ft. lbs
Exhaust Manifold to Cylinder Head Bolts — tightening sequence 1 stages
111 ft. lbs., step 2: 1811 ft. lbs
Intake Manifold to Engine Bolts — tightening sequence 1 stages
13.7 ft. lbs., step 2: 7.43.7 ft. lbs
Exhaust Manifold to Cylinder Head Bolts — tightening sequence 1 stages
111 ft. lbs., step 2: 1811 ft. lbs
Main Bearings — tightening sequence 1 stages
118 ft. lbs., Step 2: 18018 ft. lbs

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 7,500 mi; spark plugs every 100,000 mi; coolant at 150,000 mi. The big-interval services (at 150,000 mi for coolant, and the transmission fluid) are the ones owners most often skip — on a lower-mileage example, assume the original fluids are still in it and check them first.

Every 7,500 miCV Joint Boot (inspect) · Drive Axle Assembly (drain & refill) · Driveshaft (inspect) · Engine Oil Filter (replace) · Tire & Wheel Assembly (rotate)
Every 30,000 miEngine Air Filter Element (replace) · Fuel Filter (replace)
Every 50,000 miTransfer Case Assembly (drain & refill)
Every 100,000 miSpark Plugs (replace) · Transmission Fluid & Filter (replace)
At 150,000 miEngine Coolant System (drain, flush & refill) · Engine Coolant System Hoses (inspect) · Radiator Cap (inspect)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

Owner complaints about the 2003 Isuzu Ascender 4WD top in one area — the exterior lighting, 5 of 35 reports (14%), well ahead of the next concern. None of this vehicle's 5 recall campaigns target the exterior lighting, so those reports read as owner-reported wear-and-tear rather than an acknowledged defect. 2 of the reports describe a crash and 0 a fire — a small share of the total, but worth weighing against the exterior lighting pattern above. These are tallies of what owners actually reported to the federal government, not an editorial score — and higher-selling models naturally rack up more reports.

5
Open recalls
NHTSA campaigns
168
Service bulletins
Manufacturer communications
1
ODI investigations
Office of Defects Investigation
35
Owner complaints
2 involved a crash · 0 a fire

Owner complaints filed with NHTSA, by component

All 35 complaints on record, top 8 components.

Exterior Lighting5
Electrical System4
Fuel System, Gasoline4
Power Train3
Steering2
Electrical System,Exterior Lighting2
Service Brakes1
Engine & Engine Cooling1

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 5 campaigns on record for this vehicle.

03V269000Equipment:Other:Owners/Service/Other ManualReported 21/07/2003

CERTAIN SPORT UTILITY VEHICLES FAIL TO COMPLY WITH THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 225, "CHILD RESTRAINT ANCHORAGE SYSTEM." THE OWNER'S MANUAL DOES NOT EXPLAIN THE MEANING OF THE LOCATION… Remedy: OWNERS WILL BE PROVIDED WITH A SUPPLEMENT FOR THEIR OWNER'S MANUAL. IT DESCRIBES AND SHOWS THE LOCATION SYMBOLS FOR THE CHILD RESTRAINT ANCHORS THAT ARE LOCATED IN THE VEHICLE…

03V213000Power Train:Automatic TransmissionReported 05/06/2003

CERTAIN SPORT UTILITY VEHICLES FAIL TO COMPLY WITH THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 114, "THEFT PROTECTION." THESE VEHICLES ARE EQUIPPED WITH A MECHANICAL OVERRIDE THAT COULD ALLOW THE… Remedy: DEALERS WILL ELIMINATE THESE CONDITIONS BY DISABLING THE OVERRIDES. OWNER NOTIFICATION BEGAN JUNE 13, 2003. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED…

Technical service bulletins NHTSA · verified

Showing 5 of 168 bulletins on record with NHTSA.

BulletinDateComponentSummary
IB13-R-001G2023-05-08Unknown Or OtherThis bulletin outlines the procedures for using the Alpine Exchange Program (the…
WB13-X-001B2022-08-30EquipmentIsuzu Commercial Truck of America, Inc. (ICTA) is providing the following procedural…
WB13-X-001A2022-08-02EquipmentIsuzu Commercial Truck of America, Inc. (ICTA) is providing the following procedural…
IB09-X-002B2022-07-20EquipmentThe following is a list of the Isuzu-recommended Threebond product part numbers…
IB09-X-004C2022-07-20Engine And Engine CoolingThe Isuzu Commercial Truck of America (ICTA) Service Technical Assistance Center (TAC)…

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420
Catalyst system efficiency below threshold — Bank 1
P0300
Random / multiple cylinder misfire detected
P0171
System too lean — Bank 1
P0455
Evaporative emission system leak detected — large leak
P0128
Coolant thermostat below regulating temperature
P0442
Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN
Decode a VIN to confirm the transmission and build data for a specific Ascender 4WD. OEM
Build data
Plant, GVWR class, engine and body data for any 17-character VIN.
Recalls
Check open recall campaigns against a specific vehicle by VIN.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Group 78 batteryEngine oil filter 8889842150Engine air filter 8192397130Fuel filter 8889830680Spark plug 2901230720

Reference guides

Cross-vehicle references for the kinds of data on this page.

Vehicle recalls & TSBsOBD-II trouble codesTorque specificationsMaintenance schedulesFluid capacities & specs

Frequently asked

Does the 2003 Ascender 4WD have open recalls?

NHTSA lists 5 recall campaign(s) for this model year. Check your specific vehicle by VIN.