A number of Jeep Liberty’s have this no crank condition caused by broken actuator pin inside the Ignition Switch Actuator Shaft as this is very common. This is the mechanical pin from the ignition lock cylinder to the electrical part of the ignition switch which can and will prevent the engine from cranking over when it breaks. Usually this happens at around 100,000 miles but can happen well before that. Below I will take you through one that came in because of this condition and walk you through this diagnoses.
This 2006 Jeep Liberty came in as a no crank condition. Customer indicated that one morning the vehicle would not crank over so he decided to get it towed into the shop. Upon checking, the ignition did not appear to come up or power up with the key turned to the “on” position. I was able to verify this by locating fuse number 14 in the fuse block and confirmed there was no power on this circuit with the key “ON”. This circuit should be powered up when the key is turned “ON” as this is part of the ignition circuit.
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Starter relay operation
Before we dive into things, I wanted to supply you with the starter relay operation. This relay consists of an electromagnetic coil, a resistor or diode, and three (two fixed and one movable) electrical contacts. The movable (common feed) relay contact is held against one of the fixed contacts (normally closed) by spring pressure. When electromagnetic coil is energized, it draws the movable contact away from normally closed fixed contact, and holds it against the other (normally open) fixed contact.
When electromagnetic coil is de-energized, spring pressure returns movable contact to normally closed position. The resistor or diode is connected in parallel with electromagnetic coil within relay, and helps to dissipate voltage spikes produced when coil is de-energized.
Let me repeat that in English for you. Basically, there are contacts inside the relay that close to allow power through the relay down to the starter when it is energized. Some relays get activated or energized by a power source (Battery +) while others get grounded to activate. Either which way will work. However, the engineers that desinged this vehicle decided to control this relay with two inputs. The ignition switch input (which is a power supply, which will only work if the actuator pin has not broken inside the ignition switch actuator shaft) and a ground signal sent by the Engine Control Module or computer. (More about this below)
Power supply to the relay
The starter relay is protected by at least 2 different fuses on this year Jeep. They are a 40 amp fuse number 8 and a 15 amp fuse number 28 both located in the Power Distribution Center or PDC under the hood.
Now that we know how the starter relay operates, my next step was to go directly to the starter relay and check the inputs. The starter relay is located in the Power Distribution Center or PDC located in the engine compartment. In theory, if the starter relay has power going into it on even one terminal and the signal wire from the relay to the starter is good, I should be able to install a jumper wire and get the starter to crank the engine over. Using the right wiring diagram you can get here, I was able to see how the starting circuit works and map out the best course of action to take when diagnosing this no crank condition.
I jumpered terminal 30 to terminal 87 of the starter relay and the engine cranked over. This verifies a few things in starting circuit. First, we know the starter is good and working like it should. Next, we know the wiring down to the starter is good and we also know the power supply (and wiring) going into the starter relay is good on terminal 87.
That leaves us with two other terminals going into the relay we need to check. These are terminals 85 and 86.
Terminal 86 gets power on the light blue/red that comes directly from the electrical part of the ignition switch when the key is in the CRANK position only. This is the crucial part of the test. This is where you can verify that the ignition switch is in fact sending a signal or not to the starter relay. If the ignition switch actuator shaft was broken, this circuit will not be powered up in the CRANK position.
Terminal 85 of the starter relay is grounded or controlled by the Engine Control Module after it verifies the transmission is in Park or Neutral. This is very important. To do this, your best bet would be to use a scanner or scan tool to verify that the transmission is in Park or Neutral while looking in the scan data. In addition, the Engine Control Module may not work or be able to ground this circuit if it is not powered up and awake. There are a number of things that can factor into this. The ECM may be missing power or a ground preventing the ECM from powering up. In addition, the reference voltage from the ECM to various sensors may be getting shorted out due to a faulty/shorted sensor. (Based on my experience, this is usually a camshaft position sensor or crankshaft position sensor.) Last but not least, the ECM itself may simply just be bad not powering up preventing the engine from cranking over.
Here is a tech tip: Ground pin #38 of the C3 connector at the Powertrain Control Module (PCM) and see if vehicle cranks over. This will be a dark green wire with orange stripe. This test verifies the integrity of the wiring between the PCM and starter relay.
Engine Control Module ignition switch input
The ECM needs to know when the ignition switch is in the “CRANK” position in order to ground or activate the starter relay on terminal 85. It can only do this once it sees that ignition switch is in the CRANK position. How does it know when this occurs? There is a seperate circuit from the ignition switch (pin 2) to the ECM (pin 19 pink/white wire) that provides power into the ECM when the ignition switch is in the CRANK or START position. However, if the actuator pin inside the ignition switch actuator shaft is broken, this circuit will not be powered up by the ignition switch. This means when testing at the starter relay, you will not see a ground from the ECM to pin 85 (Dark Green/Orange wire). So be sure to keep that in mind when doing your testing.
Here is a list of vehicles I have put together that use this type of set up and have this ignition switch actuator shaft that is likely to break causing this no crank condition.
2005 Chrysler Town & Country 3.8
2006 Dodge Dakota 3.7
2005 Dodge Durango 3.7
2007 Dodge Nitro 3.7
2007 Jeep Commander 3.7
2006 Jeep Grand Cherokee 3.7
2000 Jeep Grand Cherokee 4.0
2004-2011 Jeep Liberty 3.7
As it turned out, the Linkage was broken between the lock cylinder and the ignition switch preventing the electrical part of the ignition switch from turning preventing the engine from starting. Last I checked, this part is not available from the Dodge, Jeep, Chrysler Dealerships. They recommend to replace the entire steering column if this actuator pin is broken between the lock cylinder and ignition switch. However, the good news is Dorman has got you covered. They make this part aftermarket and it works very well. It is Dorman part number is 924 – 704. You can get this part here on amazon for much cheaper than you can purchase a new steering column from the Jeep dealership. I would recommend to go that route. In fact, that’s what we did and the customers vehicle started right up and ran like new.
Linkage is broken between the lock cylinder and the ignition switch.