Recently I came across a 2004 Saturn Ion that would not start intermittently cold or when wet (like after it has been raining outside). The customers complaint was an intermittent “no crank” condition. Turn the key and sometimes it would not crank over at all (starter did not activate). This is very interesting and it turns out this is a very common problem on the 2003-2006 Saturn as well as many other new vehicles with the same type ignition switch and/or starting circuit set up. So in this this article, I though I would share you my findings on this vehicle. I will cover the theory and operation, how to diagnose this no crank condition, share an important Factory TSB related to this concern, and provide you with the correct fix for this 2004 Saturn Ion no crank/start condition.
Checking the Starting circuit.
First the small things needed to be checked by doing some preliminary checks. We found that the Battery, Starter and PNP switch (Park Neutal Position Switch) or TRS (Transmission Range Switch) were all in good working condition and tested/verified as good. In addition, the security light was not on or flashing with the key on or when trying to start the vehicle so that indicates that this issue is not related to the security system. Although we did not have any reason to believe this was a security related issue preventing the engine from cranking over, we attempted to try the GM relearn procedure anyway just to be sure. After confirming that did not work and the vehicle still was not starting, it was time to do some diagnosing. Upon checking for codes in the computer using my diagnostic scanner I found no DTC’s present in the ECM or Engine Control Module. I did however, find Diagnostic Trouble Codes B2960 and B3033 stored in the BCM or Body Control Module.
Diagnostic Codes B2960 and B3033
These two codes are often flagged by the Body Control Module when the Pass-lock sensor inside the ignition switch goes bad. While I don’t have the exact information about these two codes, from what I understand, these codes will be generated by the BCM when it sees a difference in the voltage signal from the Pass-lock Sensor when the key is rotated from the off position to the ON or START position compared to the previous “learned” value. The actions taken by the Body Control Module when these codes appear: The BCM will enter “Security mode”, prevent the engine from cranking and will illuminate or flash the security telltale on the instrument cluster. (I wish I had more information for you on these codes, sorry!)
2003-2006 Saturn ION Starting Circuit Description and Operation
To be able to diagnose this no crank condition, it is important to understand how it works. The BCM or Body Control Module sends out a 5 volt reference to the ignition switch on the white/black wire. When the ignition switch is turned to the CRANK or START position, the voltage being sent back to the BCM is much less because there is a built in resistor inside the ignition switch which lowers the voltage. (The signal wire from the ignition switch back to the BCM is the white wire) From there, the BCM knows when the key is turned to the CRANK or START position. The BCM then sends a signal to the ECM or Engine Control Module over the GM class two serial data circuit. The ECM will then ground or activate the starter relay, the contacts inside the relay will close and will then send power out down to the starter motor to crank the engine over.
Technical Tip: On this 2004 Saturn Ion, the PNP switch powers up the starter relay when the transmission is in park/Neutral after going through the IGN fuse 11 located in the under-hood fuse block. The 30 amp crank fuse number 46 powers up the other side of the starter relay.
Technical Tip: The Body Control Module sends a signal to the Engine Control Module over the GM class 2 Serial data circuit on the purple wire. It leaves the BCM from pin 27 connector 3 and goes to pin 12 of connector 1 of the ECM.
Checking for Technical Service Bulletins
One thing that that always needs to be done doing any diagnosing is to check for Factory TSB’s related to the vehicles concern. A lot of times there are Factory related TSB’s released by the Manufacture specific to the concern you may have on a particular year, make and model vehicle. This will help save time and money when trying to diagnose and fix the vehicle. In addition, it can make you aware of any factory defects that are current with your vehicle. On this Saturn Ion, I have located a FACTORY Technical Service Bulletin or TSB about this no crank/start condition that was released by General Motors. It is TSB #04-08-45-005D: Released MAR 15, 2006. This TSB applies to 2003-2006 Saturn ion no crank, intermittent no crank and possible Diagnostic trouble code or DTC B2960 and/or B3033 stored in BCM.
This no crank/no start condition on this 04 Saturn Ion is caused by a faulty ignition switch (you can get here) and a software update for the Body Control Module. What happens is when the key is rotated from run to the start position, there is a voltage signal sent to the BCM that goes through the Pass-lock Sensor Resistor in the Ignition Switch. This voltage signal may be bad or get interrupted when going from run to start that the BCM interprets as a failure in the pass lock system and disables the starting circuit. As the above TSB describes, this voltage signal may have an early ignition switch “bounce” (when going from RUN to START) which the BCM interprets as a failure in the Pass-lock circuit triggering this security system which results in this no crank/start condition. This TSB #04-08-45-005D instructs the technician to verify that the ignition switch has been replaced using the updated part number 10392423, (if not, replace it) and then reprogram the BCM (as needed) and then finally perform the 30-Minute Learn Procedure. This will fix the no crank/no start on this 2004 Saturn Ion that we were working on. However, there have been cases where the Body Control Module may need to be replaced as a last resort if the engine still does not crank over after completing the steps in this TSB. The ignition switch input and the power mode are correct, there are no other inputs disabling cranking, and the Body Control Module (BCM) is not commanding cranking, the BCM is defective and will need to be replaced.
Technical Tip: There have also been cases where this issue is fixed by simply replacing the ignition switch with the updated part number and then doing the 30 minute relearn procedure. I would recommend to go this route if you are a do-it-yourselfer. But keep in mind, the BCM may still need to be updated or even replaced.
Technical Tip: A clicking noise may be noticed when the key is first turned to the START position, but there will be no noise heard after the initial start attempt.
Testing the Starting System using a Scanner
Hands down the absolute best way to diagnose this condition is to use a scanner hooked up to the OBD2 or diagnostic connector under the dash on the drivers hand side. Here you can read live engine data and communicate with the Saturn Ion’s Engine Control Module and Body Control Module. Since we now know how the starting circuit operates, it is important to view the data in BOTH the ECM and BCM. Looking at the live data in the BCM, you are going to want to see that the ignition switch is in the START or RUN position while you turn the key to the CRANK position. While looking at the live data in the ECM, you are going to want to see a “CRANK” request being sent from the BCM and that the ECM is activating the Starter Relay. That way you know the ignition switch, the Body Control Module, Engine Control Module and the rest of the starting circuit is all working normal.
Another thing you can do is to do a self test on the starting circuit using the bidirectional controls if your scanner supports this function. Basically, you would command the starting circuit to operate using the scanner hooked up to the Diagnostic Connector and the engine should crank over. This will verify the integrity of the BCM, ECM and starting circuit wiring to ensure they are working properly. While some scan tools do not have this function, some more expensive ones do. If your going to purchase one that would be worth investing into that does bidirectional controls, I recommend the Autel MaxiSYS MS906. It covers more than 40 US domestic, Asian and European vehicle brands, has your bidirectional controls, connects to your local Wifi and does not bust the bank as you can pick it up for a reasonable cost (not to mention the seller has great feedback too!).
The fix for this 2004 Saturn Ion no crank/start condition was to replace the ignition switch with the updated part number, update the Body Control Module with the latest software version available and then finally do the 30 minute ignition switch relearn procedure. Here is the updated part numbers you will need.
Updated Ignition switch assembly: Part Number 10392423
Body Control Module (2003 Saturn Ion) 15797057
Body Control Module (2004 and 2005 Saturn Ion) 15797058
Body Control Module (2006 Saturn Ion) 10390022
Note: While they all use the same ignition switch (same part number), you will see that the BCM may be different depending on the year Ion.
Related Saturn Ion TSB’s
#02-06-04-015A: INTERMITTENT NO CRANK, NO START (MAR 7, 2006)
#PIC3404: PASSLOCK RELEARN PROCEDURE SELECTION FOR ION AFTER REPLACEMENT OF A PASSLOCK SYSTEM COMPONENT (FEB 22, 2005)