After Genuine Parts Company GPC and Harley-Davidson, Inc. HOG kick-started the Q1 earnings season with a positive surprise, investors are now looking forward to the next bigwigs – General Motors Company GM and Johnson Controls Inc. JCI, which are slated to report results this week.The general mood is somewhat pessimistic due to falling first-quarter estimates over the last three months. As per our Earnings Preview report, total S&P earnings for the first quarter are expected to be down 10.3% on a 0.6% decline in revenues. Earnings growth is projected to be positive for only 6 of the 16 Zacks sectors. However, the outlook looks bright for the Auto sector, which is expected to record the largest year over year growth among all the sectors.The auto industry witnessed a good start to the year, with strong U.S. sales by major companies. However, the yet-to-recover Chinese economy, sluggishness in other emerging markets and numerous safety recalls are challenges for the sector. Among the many companies scheduled to report this week, let’s see what awaits these two major auto stocks that are going to release their results on Apr 21.General Motors has an Earnings ESP of -0.99% for the first quarter of 2016 and a Zacks Rank #3 (Hold). The Zacks Consensus Estimate for the quarter is pegged at $1.01.General Motors sold 683,698 vehicles in the U.S. in first-quarter 2016 with retail sales rising 7.8% during the quarter. Higher quarterly retail sales should lead to better revenues. In addition, General Motors has been gaining new contracts for business expansion. The automaker is also focused on investment in innovative technologies and vehicles, which should provide sustained growth. However, General Motors has been facing a challenging situation due to a delay in the recall of 2.6 million vehicles with defective ignition switches. Recently, the company settled the third ignition switch case among the six cases which were supposed to go on trial this year. This may weigh on the company’s financials.However, General Motors has beaten the Zacks Consensus Estimate in 3 of the trailing 4 quarters with a positive average surprise of around 12.10%. (Read more: Is General Motors Poised to Beat on Q1 Earnings?)Johnson Controls has an Earnings ESP of 0.00% for the second quarter of fiscal 2016 (ended Mar 31, 2016) and a Zacks Rank #2 (Buy). The Zacks Consensus Estimate for its earnings is pegged at 82 cents per share.Johnson Controls expects earnings per share to increase 10%–14% over the second quarter of fiscal 2015. Revenues should benefit from improvement in results in the Building Efficiency and Power Solutions segments as well as higher automotive production. However, negative foreign currency translation, which had affected Johnson Controls’ past results, poses a concern.The company delivered mixed earnings surprises in the last four quarters. It outperformed the Zacks Consensus Estimate in 2 of the trailing 4 quarters with an average beat of around 1.13%. (Read more: Can Johnson Controls Earnings Pull a Surprise in Q2?)Check back later for our full write-up on the earnings releases of these stocks.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report JOHNSON CONTROL (JCI): Free Stock Analysis Report GENUINE PARTS (GPC): Free Stock Analysis Report HARLEY-DAVIDSON (HOG): Free Stock Analysis Report GENERAL MOTORS (GM): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research