The U.S. National Highway Traffic Safety Administration said yesterday it is opening a formal investigation into reports of lapses in the antilock braking system on Toyota Motor Corp.’s 2010 Prius hybrid sedan.

NHTSA says it has received 124 reports about Prius braking, including four accidents and two injuries. The probe involves 37,000 cars in the U.S. Drivers complain of an occasional lapse in brake responsiveness on bumpy or icy roads. If the agency finds evidence of a defect, it would upgrade the probe to an engineering analysis, which is often the precursor to a recall.

Japan’s transportation ministry, which has received 38 complaints about Prius brakes, told Toyota earlier this week to investigate the issue. The company says it has received 77 complaints in Japan.

The Nikkei reports Toyota plans to announce a recall of 176,000 Priuses in Japan and about 100,000 in the U.S. to fix the ABS software. The Japanese newspaper, which doesn’t cite its sources, suggests the company will launch recalls or offer free repairs in other markets.

Priuses from the 2004-2009 model years are involved in a separate recall of 5.4 million vehicles in the U.S. to fix floor mats that can jam the throttle pedal.

Analysts say the Prius investigations are worsening Toyota’s credibility crisis, which was triggered by recalls of about 8 million vehicles worldwide to fix problems with floor mats and sticking accelerator pedals. The actions strike at the twin pillars of Toyota’s reputation: quality and environmental leadership, which is tied to hybrids such as the Prius.

Toyota Motor Corp. unexpectedly declared yesterday that it has known about glitches in the antilock braking system of the 2010 Prius hybrid sedan for several months and has rewritten the ABS software to fix the problem in Priuses rolling off its assembly lines since late January.

But Toyota didn’t notify regulators or owners of vehicles already on the road, contending the phenomenon is not a safety risk.

The company explains when the Prius’ ABS engages, there may be a “pause” in braking force of less than one second as the car switches from regenerative mode to standard hydraulic braking. The company says hard pressure on the brakes will overcome the problem. Toyota says that even with the delay, the Prius’ stopping distance meets regulatory standards.

Because the problem occurs when the ABS system engages, most complaints involve braking while driving over slick roads or potholes. Toyota says this also explains why the number of reports escalated sharply this winter. The company has been selling the latest-generation Prius since May 2009.

Toyota says it also is examining the new Toyota Sai and Lexus HS250h hybrid sedans, which use the same braking system as the 2010 Prius.

By 2014, two-thirds of Ford Motor Co. and General Motors Co. vehicles in North America will be built on global platforms, up from about 10% now, according to a new report from consulting firm Grant Thornton LLP.

The consulting firm told the Automotive Press Assn. in Detroit yesterday that domestic automakers will slash their total number of vehicle platforms to 29 by 2014 from 40 last year. Chrysler is behind its rivals because it only began moving to global platforms via the alliance it formed with Fiat SpA last June.

Moving to fewer platforms will bring Ford and GM in line with Asia’s largest automakers, which benefit from the economies of scale of producing large numbers of vehicles from a single platform. Last year GM averaged 100,000 units per platform, while Honda averaged more than 250,000 units.

The trend ups the ante for suppliers, since automakers will be awarding larger parts orders for upcoming vehicles to fewer companies. Grant Thornton says this year will be critical for suppliers because most of the parts contracts for vehicles arriving in 2014 will be assigned by this time next year.

Global consolidation can lower engineering costs, increase flexibility and reduce complexity. But Grant Thornton notes it also leaves automakers vulnerable if they find a defect in a part used in many models worldwide. Witness Toyota Motor Co.’s current major recalls, which includes one to repair sticking accelerator pedals in 4.7 million vehicles. Even so, Grant Thornton says carmakers must adopt global platforms to achieve the scale needed to survive.

Toyota Motor Corp. posted a $1.7 billion net profit in the fiscal third quarter ended Dec. 31, compared with a $1.8 billion loss a year earlier, as revenue increased 10% to $59 billion in the latest quarter.

Toyota attributes the improvement to cost cutting and a 12% jump in demand to 2.07 million vehicles.

As demand revives in many parts of the world, the company hiked its forecast for the fiscal year ending March 31. Instead of the $2.2 billion loss it projected earlier, Toyota now expects a net profit of 80 billion yen ($892 million), compared with a $4.9 billion loss the previous year.

Toyota predicts a 10% year-over-year decline in revenue to 18.5 trillion yen ($206 billion). The company expects to sell 7.18 million vehicles in the current fiscal year, up from its earlier forecast of 7.03 million units. Toyota sold 7.57 million vehicles the previous year.

The company says the revised forecast includes the impact of two current recalls totaling about 8 million vehicles worldwide to fix problems with floor mats and sticking accelerator pedals. The outlook does not include any expenses related to new investigations into the braking system on the 2010 Prius hybrid.

Toyota says it expects the two existing recalls to cost about 175 billion yen ($1.5 billion) during the current fiscal year. That includes about $840 million from an estimated loss of 80,000 units of volume in North America and 20,000 in Europe and elsewhere by March 31. Analysts say that forecast may be too optimistic. The company says it can’t yet predict the impact of its quality troubles on its performance in the fiscal year beginning April 1.

Ford Motor Co. says it is offering a software upgrade on 17,600 Ford Fusion and Mercury Milan hybrid sedans to change the brake pedal feel to eliminate the occasional impression that the brakes have failed. The issue is similar to the one expected to prompt Toyota Motor Co. to recall current-model Prius hybrids.

Ford says the problem occurs when the car switches from regenerative braking to conventional hydraulic braking. The brake pedal may drop and the brake-system warning lights illuminate. The company contends that the vehicles maintain full braking capability.

Consumer Reports magazine confirms that one of its engineers experienced the phenomenon while testing a hybrid Fusion. The magazine says the driver overshot a stop sign when he thought the brakes failed. But CR says it determined the brakes did not fail. The magazine reported the incident to Ford and praises the company for its quick response.

Ford is calling the action, which applies to 2010 models built before mid-October, a “customer satisfaction program,” not a recall, because it says there is no safety problem. The National Highway Traffic Safety Administration has received one consumer complaint.

The number of U.S. auto dealerships fell to 18,840 last year from 20,450 in 2008, as Chrysler Group LLC and General Motors Co. terminated franchise agreements while in bankruptcy, according to Detroit-based consulting firm Urban Science Inc.

It was the sharpest drop in dealer ranks since at least the 1950s and double the number of dealerships that closed in 2008, the firm says. Last year’s 8% decline compares with typical annual attrition of 1%, Urban Science says. Chrysler dropped 789 dealers in June, and GM told 1,300 dealers it would cancel their franchises by this October.

Ford Motor Co. says it isn’t ready yet to decide whether it will build a new $600 million car assembly plant in Thailand, but it did not offer any further explanation.

Thailand’s Prime Minister Abhisit Vejjajiva tells reporters Ford has threatened to build the plant elsewhere in Asia if the government can’t resolve environmental challenges to new industrial construction in eastern Thailand.

Ford is eyeing a site in Rayong next to an existing plant run by its joint venture with Mazda Motor Corp., which builds cars and pickup trucks for local and export markets.

A Thai administrative court issued an injunction in September that suspended 76 proposed investments in the Rayong region until the government sets up an environmental impact assessment process. Ford’s proposed plant was not among the suspended projects. But Thai environmental activists concerned about increasing industrial pollution hope to block other corporate projects. Bangkok, which worries that delays could cause foreign manufacturers to shun Thailand, is seeking to overturn the injunction.