Limp mode on cold startups

[madridalejandro]

I’m having an issue where every time I go to start my jeep tj it’s automatically in limp mode. Unless I drive it a few miles and turn it off and on again it goes back to normal. Im guessing it’s an electrical or tcm problem. What should I check to test out my pcm and tcm before I send either out to wranglerfix. My fluid looks okay.

 

[macleanflood]

You have a code reader? A $30 Bluetooth ODB dongle and the free app Torque Lite would let you read codes and monitor live ODB data.

-Mac

 

[madridalejandro]

You have a code reader? A $30 Bluetooth ODB dongle and the free app Torque Lite would let you read codes and monitor live ODB data.

-Mac

I have an OBD reader. The most recent code I have is P0505, which I'm guessing is the PCM. Would the live OBD be useful?

 

[macleanflood]

Would the live OBD be useful?

Might be. Can you clear the code and does it come right back?

Have you pulled the connectors off the PCM and checked for corrosion?

No experience with the 04... mine is a 97...but someone else might chime in...my gut instinct tells me to check the cam position sensor sync.

-Mac

 

[madridalejandro]

Might be. Can you clear the code and does it come right back?

Have you pulled the connectors off the PCM and checked for corrosion?

No experience with the 04... mine is a 97...but someone else might chime in...my gut instinct tells me to check the cam position sensor sync.

-Mac

Yeah, code comes right back. Connectors look good, but I haven't done more than look at them. Sometimes need to give it gas on cold starts, and it also sometimes surges to 1300 rpms at red lights.

 

[JKP]

Clean the throttle body, specifically the IAC passage.

Check for disconnected/cracked vacuum lines.

 

[madridalejandro]

Clean the throttle body, specifically the IAC passage.

Check for disconnected/cracked vacuum lines.

I cleaned it the way @Jerry Bransford had it written up somewhere, it slightly helped but the problem is still there.

 

[JKP]

The IAC may be going out, also check the IAC wiring.

 

[madridalejandro]

The IAC may be going out, also check the IAC wiring.

What’s the best way to check the wiring, just have a look at it back to the pcm? Or use a multimeter to check it

 

[madridalejandro]

I replaced the IAC not too long ago, trying to solve the weird idle issue. Don't think its related to the limp mode as it wasnt there before

 

[macleanflood]

Could be a cracked intake manifold. Or just loose. Try checking the intake and exhaust bolts and make sure they're properly torqued.

-Mac

 

[JKP]

Go to the Resources section and download the FSM for 2004, open the PDF, click on Powertrain, go to P0505. The troubleshooting instructions follow this:

 

[madridalejandro]

Went back and looked into the transmission codes and a p0605 came up with the p0700. It eventually goes away if I keep turning on and off the jeep but not always.

 

[macleanflood]

Have you talked to @Wranglerfix yet?

-Mac

 

[madridalejandro]

Have you talked to @Wranglerfix yet?

-Mac

I sent them an email and planning on sending both my tcm and pcm to them but want a second opinion before I drop the cash.

 

[madridalejandro]

Bc I’m not sure if it could also be a wiring issue

 

[macleanflood]

Bc I’m not sure if it could also be a wiring issue

Only one way to figure that out...one wire at a time and a multimeter doing ohm and continuity checks.

-Mac

 

[madridalejandro]

I looked at it yesterday using this video, and everything checked out.
View: https://youtu.be/u-wH90Oqfkk?si=OWzqszqQ-TNeZylB
Wranglerfix order has been made. Thanks

Only one way to figure that out...one wire at a time and a multimeter doing ohm and continuity checks.

-Mac