If the engine runs, the gauge cluster issue is unrelated. If the engine does not run, the gauge cluster issue is a symptom, not a root cause.
Here is some relevant info I have gathered:
If you have both a P1694 and P1698 suspect a faulty Crankshaft Position Sensor (CPS). The CPS must be tested before you proceed. In the past there have been reports that the TCM has caused similar fault(s). Try unplugging the TCM and see if the NoBus message ( if present ) goes away and all gauges work. If so, replace the TCM.
Inspect and test the CPS wire plug and wire harness for loose/bent/damaged connection pins, corrosion, and damaged wires. Inspect, clean, and tighten firmly the two ground wires at the ignition coil. They also are ground locations for the transmission computer.
P1694 Fault In Companion Module. No CCD/J1850 bus messages received at the power train control module (PCM) from the AisinWarner Transmission Control Module (TCM). P1694 will set if no CCd bus messages are received from PCM for 20 seconds or invalid messages are received for 20 seconds.
Possible Causes
- Faulty Crankshaft Position Sensor.
- Faulty TCM.
- CCD Bus (-) circuit open between PCM and TCM.
- CCD Bus (+) circuit open between PCM and TCM.
- Transmission CCD bus wiring damaged
- CCD Bus (-) circuit open between PCM and TCM.
In the past there have been reports that the Transmission Control Module (TCM) failures and Keyless Entry (RKE) module failures have caused similar symptoms and faults. Note that the RKE module is on the CCD Bus. Try unplugging the RKE module and try unplugging the TCM and see if the NoBus message goes away and all gauges work. If so, replace the TCM or RKE. Engine sensor wire harness/wire plug issues, a faulty CPS, or a faulty TCM should be the first suspects for a P1694.
Read this >>
http://www.naxja.org/forum/showthread.php?t=63167
P1698 No CCD Messages Received From PCM. Bus communication failure to PCM. A "Companion DTC" was set in both the ECM and PCM.
Possible Causes:
- CCD Bus (-) circuit open between PCM and TCM.
- CCD Bus (+) circuit open between PCM and TCM.
- Engine control module (ECM) harness is open or shorted.
- Engine control module (ECM) circuit poor electrical connection.
- Failed engine control module (ECM).
Read this >>
https://www.jeepforum.com/forum/f11/...odule-1359085/
When the CPS short circuits the engine computer (PCM) shuts down to prevent damage to itself. As a result, there is no communication (P1694).
Disconnect your crankshaft position sensor then put the ignition key in the on position. If the instrument cluster voltage and fuel gauges start to work once the CPS is disconnected, then you know the CPS or CPS wires are shorted and is the root cause of the codes. You can verify this by testing the CPS and checking continuity and voltage on the CPS wires.
P1694 Diagnostic Procedure
1. Check instrument cluster gauges for proper operation. If fuel gauge and speedometer operate properly, go to next step. If fuel gauge and voltage meter do not operate properly, test the CPS.
2. Turn ignition off. Disconnect Gray PCM harness connector. PCM is located at left front of engine compartment. Disconnect TCM harness connector. Measure resistance of CCD BUS (-) circuit (White/Black wire) between TCM harness connector and Gray PCM harness connector. If resistance is more than 5 ohms, repair open in CCd BUS (-) circuit (White/Black wire). If resistance is 5 ohms or less, go to next step.
4. Measure resistance of CCD BUS (+) circuit (Violet/Brown wire) between TCM harness connector and Gray PCM harness connector. If resistance is more than 5 ohms, repair open in CCd BUS (+) circuit (Violet/Brown wire). If resistance is 5 ohms or less, replace TCM.
5. Conditions necessary to set DTC P1694 are currently not present. Inspect related wiring and harness connectors. See WIRING DIAGRAMS. Repair wiring as necessary. If no problem is found, check for broken, bent, backed-out or corroded wire terminal pins. Check for chafed, pierced or partially broken wires inside insulation. Repair as necessary.
P1391 - Intermittent Loss of CMP or CKP Signal. Loss of the Cam Position Sensor or Crank Position Sensor signal has occurred.
P1391 JEEP Possible Causes
- Faulty Crankshaft Position Sensor (CKP)
- Crankshaft Position Sensor (CKP) wire harness is open or shorted
- Crankshaft Position Sensor (CKP) wire circuit poor electrical connection
- Faulty Camshaft Position (CMP) Sensor
- Camshaft Position (CMP) Sensor wire harness is open or shorted
- Camshaft Position (CMP) Sensor wire circuit poor electrical connection.
P1391 – Possible symptoms:
(1) Random misfire/stumble/bucking/stalling, often over bumps or right hand turns or when going into reverse.
(2) Shorted out the Fuel pump/ECU power wire.
(3) A improperly indexed distributor/cam sensor may exhibit surging, light bucking or intermittent engine misfiring. This will most likely occur when the vehicle is at operating temperature and under a light load at approximately 2,000 rpm. The proper indexing procedure must be used as outlined in the service manual.
Often replacing the faulty sensor fixes the P1391 code, but not necessarily. Therefore it's important to check the following:
• Check that the Cam and Crank sensor wiring isn't routed too close to sharp metal edges, or to hot exhaust parts.
• Visually inspect the wiring at the sensor for any burn marks, bare wires, or discoloration indicative of melting / chafing of insulation
• Visually inspect the cam sensor for damage. Make sure the magnet is firmly attached. The sensor can be tested.
• Visually inspect the reluctor wheel inside the distributor or Cam Sensor.
• If everything checks out okay, then test the Crankshaft Position Sensor.
If you buy any OBD-II engine sensors,
make sure to buy genuine Jeep sensors.
Potential P1391 Fixes:
Fix #1:
Inspect your O2 wire harnesses for bent or pushed back wire plugs pins, damaged wires, chafed insulation, or failed wire splices. Use a volts/ohms multi-meter to check the resistance of the ground wire circuits from each sensor. Replace corroded ground wires/connectors and clean ground wire connection points.
Fix #2:
The timing may off. Re-index the distributor/cam sensor per the FSM instructions, or replace faulty distributor/cam sensor pickup module.
Read this article: Scan Tools, O-Scopes and Toothpicks here >>
https://web.archive.org/web/20200820085756/http://jeep.blackonyx.net/pdfs/jcss.pdf
Read this thread >>
https://www.jeepforum.com/forum/f19...352-p0353-crank-cam-sensor-issue-fix-3487474/
Testing the Throttle Position Sensor and Coolant Temperature Sensor is also a good idea.
