Common questions

Why does my Jeep Cherokee crank but not start?

Why does my Jeep Cherokee crank but not start?

Re: Cranks but will not start, no PCM function. You still don’t have spark or injector pulse; this should be looked into first. It still could be a bad crank sensor. The crank sensor sends the pulse to the PCM and then it sends the signals to the proper areas like spark, fuel relay, and injector pulse.

What kind of spark does a Jeep Cherokee sport have?

I have a 1996 Jeep Cherokee sport. I have no communication to the computer with a scanner, no check engine light, no 5 v reference, no spark. I have tried to manually pull codes with the key. The dealer says that it does not have an immobilizer by the VIN number.

How does the PCM work on a Jeep Cherokee?

When the PCM grounds the ASD relay, contacts inside the relay close and connect circuit F5 from fuse 20 in the PDC to circuit A142. Circuit A142 splices to the generator field terminal, fuel injectors, ignition coil and the upstream and downstream heated oxygen sensors. Circuit A142 also connects to cavity C12 of the PCM.

Where is the ignition switch located on a Jeep Cherokee?

When the ignition switch is in either the START or RUN position, it connects circuit A1 from fuse 8 in the Power Distribution Center (PDC) to circuit A21. Circuit A21 powers circuit F99 through PDC fuse 18.

Re: Cranks but will not start, no PCM function. You still don’t have spark or injector pulse; this should be looked into first. It still could be a bad crank sensor. The crank sensor sends the pulse to the PCM and then it sends the signals to the proper areas like spark, fuel relay, and injector pulse.

I have a 1996 Jeep Cherokee sport. I have no communication to the computer with a scanner, no check engine light, no 5 v reference, no spark. I have tried to manually pull codes with the key. The dealer says that it does not have an immobilizer by the VIN number.

What causes no start on a jeep 4.0L?

Updated: 29 June 2019. Article Id: 420. A no start condition, on your 4.0L Jeep, is usually caused by a lack of fuel, or a lack of spark, or a lack of air (generally engine compression).

What kind of ignition system does a Jeep Cherokee use?

The ignition system is the one tasked with creating and delivering spark to each of the 6 cylinders. Without spark, the engine will crank but no start. The ignition system of the Jeep vehicles covered by this tutorial use either a distributor type system or a COP (Coil-On-Plug) ignition coil system. Failed ignition coil.

Why does my Jeep 4.0L have no start?

CASE 2: Spark was NOT present in all of the cylinders (DISTRIBUTOR TYPE): This test result tells you without a doubt that the no start condition of your 4.0L equipped Jeep is due to a malfunction in the ignition system. Now, with no spark in any of the engine cylinders, this what I would suggest:

Why does my Jeep Cherokee have no spark?

I have no communication to the computer with a scanner, no check engine light, no 5 v reference, no spark. I have tried to manually pull codes with the key. The dealer says that it does not have an immobilizer by the VIN number. I have power and grounds to the PCM connectors.

Can a spark test be done on a no start Jeep?

Testing for spark can very easily and safely be done with a dedicated spark tester. If the ignition system is the cause of the cranks but does not start condition, you’re not gonna’ see spark at any of the 6 spark plug wires or 6 COP ignition coils.

What causes a jeep to have a no start condition?

The usual suspects, that can cause this type of problem, are a bad fuel pump, bad crank sensor, bad ignition coil (if your Jeep is distributor equipped), etc. Does Not Crank Condition: Means that the engine is not cranking when you turn the key to crank the engine.

Why does my Jeep 4.0L have no spark?

It’s almost impossible for all 6 COP ignition coils to fail at the exact same time… so the most likely cause for this no spark condition is a bad crankshaft position sensor. But before you go out and replace the crank sensor, you need to test it (to make sure it’s fried).

Testing for spark can very easily and safely be done with a dedicated spark tester. If the ignition system is the cause of the cranks but does not start condition, you’re not gonna’ see spark at any of the 6 spark plug wires or 6 COP ignition coils.

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Ruth Doyle