2001 GMC Yukon XL fuel system problems

What is wrong

Certain trucks and sport utility vehicles were built with fuel module reservoir assemblies that contain fuel pump wires connectors may overheat under certain operating conditions.

Risk

If the ignition circuit wire is exposed, the fuel pump fuse will blow, disabling the fuel pump and causing an engine stall or no-start condition. If sufficient heat is conducted to the pass-through connector, a hole in the connector may result, which may cause a 'service engine soon' light to be illuminated during the emission system diagnostic routine. Fuel vapor and in some cases liquid fuel may leak out of the fuel tank through the hole in the connector body. Fuel leakage, in the presence of an ignition source, could result in a fire. Also if the ignition circuit or ground wire is exposed and shorts to the fuel level sender card wires, inaccurate fuel level readings may result.

Remedy

Dealers will remove the fuel tank, and remove the module reservoir assemblies from the tank, and install a new service kit free of charge. An interim letter to owners was mailed on may 25, 2005. The owners were re-notified on october 19, 2005, since parts are now availabe. Owners may contact chevrolet at 1‑800‑630‑2438 and gmc at 1‑866‑996‑9463.

Recall number 05V155000 · Recall details

In a letter dated april 14, 2005, general motors (gm) notified odi that it had identified a defect related to motor vehicle safety in approximately 316,508 model year (my) 2000-01 1500 series chevrolet suburban and gmc yukon xl vehicles (recall 05v‑155).gm determined that some of these vehicles were equipped with fuel module reservoir assemblies (mras) that contain fuel pump wires and/or connectors that may overheat under certain operating conditions.according to gm, fuel pump wires that overheat may result in one or more conditions that present risks to motor vehicle safety:(1) fuel leakage from the mra pass-through connector if the overheating produces a hole in the plastic connector; (2) engine stall if wiring exposed by the overheating shorts to ground and causes the fuel pump fuse to blow; or (3) inaccurate fuel level readings if overheated wiring is shorted to the fuel level sender card.gm's analysis identified the cause of the overheated wiring as a high-resistance condition in the mra connector contacts due to fretting corrosion that may develop over time.gm determined that the corrosion is caused by movement between the contact surfaces and that such movement is primarily influenced by chassis and fuel tank virbration characteristics.gm's testing found that the fuel tank vibration characteristics of the recalled my 2000-01 1500-series vehicles were significantly greater than in other gm vehicles equipped with the same mra connectors.these vehicles had the highest rate of related fuel leak and stall complaints; and a recent survey conducted by gm found evidence of mra wiring over-heating in almost one-third of the 1500-series vehicles inspected. Other vehicles equipped with the subject mra connector and evaluated during this investigation include approximately 33,000 my 2000-01 2500-series sububran and yukon xl vehicles, which fall within the scope of ea04-026, and peer populations of short wheelbase yukon and tahoe utility vehicles and full-size silverado and sierra pickup trucks. These vehicles are not included in recall 05v‑155 for the following reasons:(1) these vehicles are equipped with fuel tanks with significantly less vibration at the mra interface than the recalled vehicles; (2) the potential for fuel leakage is substantially lower in the pickup trucks and short-wheelbase utility vehicles due to differences in fuel tank configuration and no incidents of fuel leakage due to overheated wiring were verified in these vehicles; (3) there there have been only three potentially related complaints of fuel leakage associated with the overheated wiring condition in the 2500-series long-wheelbase utility vehicles; and (4) no evidence of overheated wiring was found in the 2500-series suburban and yukon xl vehicles and pickup trucks inspected by gm in its vehicle survey efforts and the rate found in the short-wheelbase utilities was lower than the recalled vehicles by an order of magnitude. Odi will continue to monitor the experience in the 2500 series my 2000-01 long-wheelbase utility vehicles.the closing of this investigation does not constitute a finding by the federal safety agency that no safety-related defect exists for the 2500 series vehicles.the agency reserves the right to take further action if warranted by a change in circumstances.

EA04026

The fuel pump wiring and connector may overheat and melt a hole in the top of the fuel pump module.possible consequences include fuel tank leakage and engine stall with no restart.fourteen of the 20 complaints to odi allege fuel tank leakage, including one that reported that a fire department was called to the scene after a pool of gasoline was discovered beneath the vehicle.most of the odi complaints report incidents that occurred within the past year. According to gm, fuel leakage can occur in the subject vehicles if the heat is sufficient to melt a hole in the plastic connector large enough for liquid fuel to flow through.on-board emissions diagnostics may detect holes that are approximately 0.040 inches or more and set a service engine soon warning light.the connector position in the subject vehicles is below the fuel level when the tank is full.while gm does not know how much fuel could leak from a tank with a melted fuel pump connector, several consumers have reported significant leak events.engine stall can occur if:(1) a short occurs in the pump wiring (bare wire exposed by melted insulation shorts against a ground or ground wire) and the fuel pump relay fuse is blown; or (2) the vehicle runs out of fuel due to an inaccurate fuel gauge reading resulting from an electrical short between the fuel pump wiring and the level sensor wiring. Gm's analysis of five assemblies returned from incident vehicles determined that the condition is caused by elevated resistance/ arcing at the mra undercover b cavity terminal of the four-way 150 metri-pak connector.gm attributes the high resistance and arcing to a depressed contact arm at the 150 metri-pak b cavity female terminal.gm is continuing its investigation to complete its root cause analysis. Modular reservoir assemblies using the 150 metri-pak connectors were used by gm in several million c/k-series sport utility vehicles and pickup trucks from my 1997 through 2002, when gm released a metal mra cover and a 280 metri-pak connector in the subject vehicles.during pe04-042, odi collected information from gm concerning my 2000-2002 c/k SUV's and pickup trucks.the subject vehicles comprise approximately 9 percent of production for those vehicles and about 39 percent of complaints to gm. This investigation has been upgraded to an engineering analysis to further assess the scope, frequency, and safety consequences of the alleged defect in gm c/k-series vehicles.

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