I have a 1998 Jeep Cherokee, 4.0, 4wd, auto trans. I just had the following system failures occur all at once: Overhead light cluster, radio, all gauges on the instrument panel, AC blowing hot. These all stopped working at the same time. car still seems to be running fine and other electrical systems, lights, horn, door locks--all are working. I checked all the fusable links--they are good. Ran a diagnostic at Advance auto and got the following fault codes: P1491, P0443, P0705, P0545.
Can you tell me what I'm looking at here and how I can fix this?
Year: 1998Make: JeepMake (other): CherokeeModel: SportEngine: 4.0 auto trans
checked fuses, ran diagnostic
Hello Mark, thank you for choosing Just Answer.
You said the fuses are good, is there power at all the fuses in the junction block at the right kick panel?
P1491 - Radiator fan relay circuit
P0443 - Evap purge solenoid
P0705 - Shifter signal to TCM
P0545 - Could not find information
I have no idea. I am assuming there is power going in because other electical systems are working. I wouldn't know how to check if this anyway.
Maybe this will help. This all occured while I was driving and the overhead light assembly (on the interior roof) fell off, ahnging by the wires. It has done this in the past, and it slides back on with no issue. While I was trying to re-seat the light assembly while driving, there was a "pop" and I lost all the systems I have previously mentioned.
I figured I had brushed the wiring or plug on the assembly on to some expoxed metal while trying to reseat it and burned through a fuse. After consulting the owners manual with no sucess, I pulled and checked every fuse and replaced them per the fuse diagram.
Checking fuses for power requires a circuit tester (voltmeter, test light, logic probe) With a test light, found at any parts store, connect the clamp to a part of the body or chassis (ground) and touch the other end, probe, to each end of every fuse. There is a small strip of metal that sticks out of each side on the back of the fuse for this purpose. The light bulb in the test lamp should illuminate if power is present. No power on one side of the fuse means it is blown and no power on either side means the voltage supply to the fuse is at fault.
Check the fuses in the underhood fuse box. Fuse #15 supplies power to the junction block for the components that are not working. If that fuse is good and there is power going through it then you need to look at the wiring.
Let me know what you find and if I can assist you further.
Where is the underhood fuse box located?
It is next to the battery.
Could this fuse be causing the codes on the OBDII?
I am going to have to say no for P0443 and P0705. Possibly for P1491 since the radiator fan relay is in the underhood fuse box. P0443 is most likely the EVAP purge solenoid. P0705 may be a sensor in the transmission. Sorry I could not find info on P0545 but it sounds like a speed control issue.
First things first, we need to have power and ground before anything can operate.
Okay, I'll give this a shot tomorrow in the daylight and let you know the results. Thanks
I have changed the fuse--which restored my radio, lights, and gauges, but I still have fault codes showing.
I tried to clear them but they keep popping up. Here is what they are:
P1491--manufacturers control aux. emission controls
P0545--exhaust gas temp. sensor low bank 1, sensor 1
P0443--evap emission control system purge valve C fault
Can you tell me WHAT these mean and what I can do to reset/fix them
OK great, glad to hear the lights are fixed.
Code P0443 is most likely a bad purge solenoid. The solenoid is located on the passenger side engine compartment connected to the firewall. It is round at the top with an electrical connector at the top and two vacuum hoses attached at the bottom. Also check all the vacuum lines for cracks as this will set an EVAP system code as well. This includes the lines at and around the fuel tank.
Code P1491 is for the radiator fan relay circuit. The control for the electric radiator fan is detecting a problem. The radiator fan relay is located in the under hood fuse box and should be labeled on the lid as for location. With the AC on and engine running this relay should be active and run the electric motor. If it doesn't, replace it with one of the other like relays in the box. If the fan still does not operate you need to check the electronics. Next to each prong of the relay is a number, 85 and 86 are the coil side of the relay. One should have power and the other ground with the AC on. If no voltage is present check the rest of the fuses. If no ground is present then you may have a PCM problem. Prong 30 is the voltage input, there should be battery voltage here at all times. Prong 87 is the relay output, there should be a ground present with the relay unplugged. A quick check of the motor circuit is to "jump" terminal 30 and 87 with a paper clip or metal object. If the fan runs then that circuit is ok. If not the motor or power supply may be at fault.
I am sorry but I cannot find code P0545 in Chrysler's database. According to the description you have provided the most likely cause is a front O2 sensor fault. Replacing the O2 sensor in front of the catalytic converter should fix this DTC.
Thank you and again please let me know if I can help you further.
5 years Chrysler, Dodge, Jeep experience. Chrysler Certified Specialist - Engine Performance