Hi, first time I’ve posted on the site so may need assistance in getting this routed into the correct category.

i have 2010 hhr with no start no crank. Ran fine no probs and following a very hot/humid day the dash display started scrolling multiple trouble codes ( tire pressure low, power steering, abs, ....). I immediately pulled it into the garage and the next morning had the no crank/no start. Thought it has to be electrical due to the humidity so checked battery voltage at the battery, ground at the battery and up front under the hood. Also checked all the relays under the hood with the multimeter and the start/crank relays are good. Pulled the starter out to inspect n clean and it works fine when I bench tested it. Checked the electrical leaf to the starter S terminal and don’t have any voltage when I turn the key to start the engine. Voltage at the starter (big cable) is showing same voltage as battery voltage (12.6 volts). Asking for suggestions on what to check next to track down why I don’t have any voltage at the starter S terminal.

 

12.6 V is a bit low but should be good enough. Did you check the 30 amp crank fuse? The park/neutral switch on the transmission?
Check the voltage on pin 86 of the start relay when you turn the key to start, that is the signal from the ECM.
Pull the plug to the ECM inspect and clean the contacts, put some dielectric grease on it.

 

Located the park/neutral safety switch and went ahead and pulled it off to test it. Elec schematic I found shows pins 1 and 12 should have continuity when in park or neutral and that’s what I found when checking. The switch (10 years old) has seen better days so I decided since I’ve got it out I’ll replace it with a new one. I live out in the sticks - so am waiting on the rockauto box to arrive. Turtle and the hare story - need to work before I can play on the car but will get it finished

 

The brown box truck brought my new neutral safety switch this morning. After installing ( you really need rubber hands and arms to remove and install this) - the 10 year old hhr woke up and started. Thanks for pointing me in the right direction

 

Since you said the old switch tested as good, try not to be too frustrated if the issue comes back. You should head to the nearest auto parts store for a free battery load test and charging system test.

Hope it really is fixed!