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Amedee
Amedee, Jeep Technician
Category: Jeep
Satisfied Customers: 25444
Experience:  ASE certified Technician advanced level specialist. Wisconsin certified emissions state inspector
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I have a 99 jeep cherokee limited, 4.0, 4x4 that will not

Customer Question

I have a 99 jeep cherokee limited, 4.0, 4x4 that will not start. Replaced the cps, still no start. When I turn key on cell is on, p1694. Relay under hood buzz when key is on, I think it is the asd relay. I have tried swapping them around with fuel pump relay and no change. Fan turns on, ac clutch engages. Starting to get frustrated with this whole thing. Any ideas?
Submitted: 1 year ago.
Category: Jeep
Expert:  Amedee replied 1 year ago.

Hello and welcome! My name is ***** ***** I can assist you with your question. Does the TPS and MAP sensor have 5 volts with the key on?

Customer: replied 1 year ago.
Expert:  Amedee replied 1 year ago.

Ok, was the PCM replaced?

Expert:  Amedee replied 1 year ago.

Start by checking for blown fuses.. especially fuse 22 as this fuse can blow due to a short causing this condition.

Expert:  Amedee replied 1 year ago.

If the PCM was not replaced and all fuses check out good, then I would suspect the PCM is going bad. Another possible cause would be any other module on board the vehicle preventing the BUS circuit from working.

Expert:  Amedee replied 1 year ago.

The other modules on board the vehicle that can go bad causing this condition are the Sentry Key Immobilizer Module (SKIM), Airbag Control Module (ACM), Transmission Control Module (TCM), Overhead Console (if equipped), Compass (if equipped) and Instrument Cluster. You can unplug these one at a time while monitoring the BUS voltage.

Customer: replied 1 year ago.
What should the voltage be? And what am I looking for exactly? A loss of voltage?
Expert:  Amedee replied 1 year ago.

Voltage where? Where would you be checking for voltage?

Customer: replied 1 year ago.
In the bus system. I also just realized my girlfriend was reading the Guage wrong on my volt meter when she was "helping" me. The tps and map sensor have only 2 volts
Expert:  Amedee replied 1 year ago.

The voltage on the BUS circuit should be 2.5 volts anytime the key is in the on position. However, if you only have 2 volts going to the TPS and MAP sensor with the key on, this indicates an issue with the PCM. I would check all powers and grounds going into the computer and replace as needed.

Customer: replied 1 year ago.
Do you know what pins exactly are what?
Expert:  Amedee replied 1 year ago.

I sure do! Test powers and grounds at the Powertrain Control Module (PCM) on the C1 connector. Pins 2 and 22 are power, then check pins 31 and 32 for ground.

Customer: replied 1 year ago.
Pin 2 has power and works on 30 and 31 I'm assuming those are the grounds being there is no 32 I see. But pin 22 has no power
Expert:  Amedee replied 1 year ago.

Try powering up pin 22. I bet it will start and run.

Expert:  Amedee replied 1 year ago.

Pin 22 gets power from fuse 22 in the PDC under the hood. This is the fuse I mentioned earlier to check

Customer: replied 1 year ago.
The fuse didn't look blown it looked in tact, but per your suggestion I changed it anyways and now it starts up. But the p1694 I believe is the code, crankshaft high circuit. I already changed the sensor twice now and the code won't clear and stay gone. I clear it and once I start up it comes right back. So I'm back to square one
Expert:  Amedee replied 1 year ago.

Back to square one minus the vehicle starting. I am glad we have made progress.

Expert:  Amedee replied 1 year ago.

P1694 NO CCD MESSAGE FROM PCM

When Monitored: Continously with Key On. Set Condition: No CCD Bus messages received from PCM for 20 seconds or invalid messages received for 20 seconds. POSSIBLE CAUSES CCD BUS(-) BETWEEN PCM & TCM OPEN CCD BUS(+) BETWEEN PCM & TCM OPEN TRANSMISSION CCD BUS WIRING DAMAGED TCM DEFECTIVE - CCD BUS OPEN

Expert:  Amedee replied 1 year ago.

I am glad I can help!

It has been a pleasure working with you. Please dont forget to honor your good faith deposit by rating my answer as "Excellent Service" for assisting you today.

Please let me know if you have any further questions.

Customer: replied 1 year ago.
Do you know which wires are the leads from the pcm to the tcm so I can ohm them out?
Expert:  Amedee replied 1 year ago.
You will actually need a wiring diagram for that. I can get one for you hit it will be after I get home from home tonight.
Customer: replied 1 year ago.
Did you ever get the wiring diagram?
Expert:  Amedee replied 1 year ago.
OMG I am so sorry I forgot. I do work all day today but will be back online tonight. Please respond back to me tonight to remind me and I'll pull a diagram for you. I'm so sorry and thanks for your patience
Customer: replied 1 year ago.
Have you had a chance to find that wiring yet?
Expert:  Amedee replied 1 year ago.

Not again! I am so sorry. Here is the BUS circuit that connects all of the modules.

Expert:  Amedee replied 1 year ago.

Hello! It's Amedee from just answer.

I am just checking in to see if you need any further assistance?

Let me know!