Hi all,
Let me start out by saying that I have read more than 40 hours on every Jeep Dodge website I could find. I have talked to multiple certified mechanics. I have been troubleshooting for over 2 months, and I could sincerely use some help.
95 Jeep Grand Cherokee 5.2 Laredo
Problem: When the key is energized in the "On" position, "Initially," there is no power to the fuel pump. CEL is not illuminated. If you leave the key in the On position for 7-30 minutes. Eventually the ASD relay will start clicking, extremely LOUD clicking. ASD relay clicks for 25-35 seconds. Then the fuel pump relay starts clicking loudly 10-20 seconds. After the relays stop clicking the fuel pump runs. The engine starts as normal.
Note: It runs with the original PCM, but you have to leave the key in the On position for 7-30 minutes before starting.
Research has shown that many people have solved this problem with a junkyard PCM.
I have tried 2 separate junkyard PCMs. Both PCMs act exactly the same way. When the key is energized to the "On" position, CEL light comes on normally, the fuel pump runs normally. But, the engine will not start. Turn key off, turn key On = fuel pump runs normally. No start.
Note: Both replacement PCM stopped all relay clicking.
Note: The interior lights have not worked since 1999 - Fuse #5 blows. Also, the hood open switch/light bulb is unplugged.
Note: When resetting the PCM. I disconnect the positive cable from the battery. Ground the positive and negative cable together for 30 seconds. Reconnect the pos cable. Turn key on, but do not start. Turn headlights on. Turn headlights off. Turn key off.
Without going into 2 months of troubleshooting...
My question is, could the factory security system prevent junkyard PCMs from starting the engine? If this is a security related problem is there a way to disable the security system when installing a new PCM?
Also, could this be a CPS issue with the new PCMs? If this is a crank position sensor problem, why does the engine run with the old PCM?
Thank you and greatly appreciated!!
Let me start out by saying that I have read more than 40 hours on every Jeep Dodge website I could find. I have talked to multiple certified mechanics. I have been troubleshooting for over 2 months, and I could sincerely use some help.
95 Jeep Grand Cherokee 5.2 Laredo
Problem: When the key is energized in the "On" position, "Initially," there is no power to the fuel pump. CEL is not illuminated. If you leave the key in the On position for 7-30 minutes. Eventually the ASD relay will start clicking, extremely LOUD clicking. ASD relay clicks for 25-35 seconds. Then the fuel pump relay starts clicking loudly 10-20 seconds. After the relays stop clicking the fuel pump runs. The engine starts as normal.
Note: It runs with the original PCM, but you have to leave the key in the On position for 7-30 minutes before starting.
Research has shown that many people have solved this problem with a junkyard PCM.
I have tried 2 separate junkyard PCMs. Both PCMs act exactly the same way. When the key is energized to the "On" position, CEL light comes on normally, the fuel pump runs normally. But, the engine will not start. Turn key off, turn key On = fuel pump runs normally. No start.
Note: Both replacement PCM stopped all relay clicking.
Note: The interior lights have not worked since 1999 - Fuse #5 blows. Also, the hood open switch/light bulb is unplugged.
Note: When resetting the PCM. I disconnect the positive cable from the battery. Ground the positive and negative cable together for 30 seconds. Reconnect the pos cable. Turn key on, but do not start. Turn headlights on. Turn headlights off. Turn key off.
Without going into 2 months of troubleshooting...
My question is, could the factory security system prevent junkyard PCMs from starting the engine? If this is a security related problem is there a way to disable the security system when installing a new PCM?
Also, could this be a CPS issue with the new PCMs? If this is a crank position sensor problem, why does the engine run with the old PCM?
Thank you and greatly appreciated!!