@Brettc24 Good afternoon from rain soaked south Florida.
This is a list of possible causes and verified fixes from Alldata.
There is also a TSB on the P0351 code that reads:
ALLDATA Diagnostic Bulletin
RELATED VEHICLES: 1993 - 1997 Cherokee, Grand Cherokee, Wrangler 4.0L. Related vehicles have similar information.
SUMMARY:
P0351 refers to these manufacturer codes:
TC-41A - Ignition Coil #3 Primary Circuit
TC-42A - Ignition Coil #2 Primary Circuit
TC-43A - Ignition Coil #1 Primary Circuit
Theory of Operation: The ignition coil is supplied 12 volts from the Automatic Shut Down (ASD) relay. The PCM controls the individual primary circuits, which fires the individual coils. The amount of dwell time is based on crankshaft speed and camshaft position.
When monitored: With battery voltage greater than 8 volts during engine cranking or greater the 12 volts with engine running and with engine RPM less than 2016, and none of the coils in dwell when checked.
Set Condition: Peak current is not achieved with battery based dwell plus 1.5 msec of diagnostic offset. It takes less than 3 seconds during cranking or up to 6 seconds while running to set.
RELATED TSB: IMPORTANT: Always refer to the most current version TSB for details.
TSB 18-14-97: Rough Running Engine with Hex Codes $28, $6A, $9B, or $BA - Apr. 4, 1997
1996-1997 (ZJ) Grand Cherokee (TJ) Wrangler with 4.0L engines and automatic transmission.
MIL illumination with the potential for a rough running engine between 2500 to 3000 RPM. The MIL may be illuminated due to one of the following DTCs:
Hex $28 - NO CRANK REFERENCE SIGNAL AT PCM, Hex $6A - MULTIPLE CYLINDER MISFIRE, Hex $9D - INTERMITTENT LOSS OF CMP OR CKP, Hex $BA - MISFIRE ADAPTIVE NUMERATOR AT LIMIT. This bulletin involves replacing the crank position sensor with a new part to allow adjustment closer to the engine flywheel.
TSB 18-03-97: Erroneous MIL Illumination/Driveability Improvements - Jan. 24, 1997
1996 - (AB) Ram Van/Wagon, (AN) Dakota, (BR) Ram Truck, (XJ) Cherokee, (ZJ) Grand Cherokee
Using the Mopar Diagnostic System (MDS) or the Diagnostic Scan Tool (DRB III) with the appropriate Diagnostic Procedures Manual, verify all engine/transmission systems are functioning as designed. If Diagnostic Trouble Codes (DTC's) are present, record them on the repair order and repair as necessary before proceeding further with this bulletin. If no DTC's or those listed above are present and any of the above symptoms have been experienced, perform the Repair Procedure. This repair involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (calibration changes) for all conditions listed.
TSB 08-35-93: No Start, Hard Starting or Poor Performance - Aug. 13, 1993
1993 (ZJ) Grand Cherokee/Grand Wagoneer equipped with a 4.0L engine and a 42 RE transmission built before MDH 05-28-XX.
No start, hard starting or poor engine performance caused by internal shorting of the secondary winding of the ignition coil.
If the vehicle exhibits any of the symptoms described above and is within the build date range, install a low resistance ignition coil and a jumper
harness which contains an external resistor.
TSB 18-04-92: No Start/Poor Engine Performance - Jun. 15, 1992
1993 (ZJ) Grand Cherokee
Poor engine performance/no start can be caused by an intermittent electrical connection at the 3-way crank position sensor wiring harness connector. Verify that the 3-way crank position sensor wiring harness connector does not have any terminals that are pushed out of place. Reinsert backed out terminals fully into the insulator and ensure that they are locked in place.
PROBABLE CAUSES:
- Crankshaft Position (CKP) Sensor Malfunction
- Ignition Coil Malfunction
- PCM Programming or Malfunction
RELATED COMMUNITY CASES: P0351, Engine cranks but will not start
DIAGNOSIS:
IMPORTANT: Follow any related TSB procedures before proceeding.
1. Visually inspect related wire harness and connectors. Look for broken bent pushed, out or corroded terminals, chaffed, pierced, or partially broken wires. Verify the CKP is installed correctly, and the sensor to spacing is correct.
—> If any problems are found, make the necessary repairs and retest.
—> If No problems are found, proceed to the next step.
2. Engine running. Manipulate the CKP wire harness to PCM connector. Verify if the engine starts to miss or stall.
—> If any problems are found, make the necessary repairs and retest.
—> If No problems are found, proceed to the next step.
3. Using the wiring diagram as a guide, verify CKP power, ground, and signal circuit operation.
—> If any problems are found, make the necessary repairs and retest.
—> If No problems are found, replace the CKP sensor.
IMPORTANT: Many Techs are reporting problems with some aftermarket CKP sensors. Make sure the CKP sensor meets OEM specifications.
| Mileage | Symptoms | Test Performed |
| 100,000 - 150,000 | Hard Start
Rough Idle
Stalls
MisfireCuts OutChuggles
Intermittent | None Indicated |
| Systems | DTC Codes | Keywords |
| Computers and Control Systems | P0351
TC-41A
TC-42A
TC-43A | None Indicated |
Comment(0)3 Repair(s) Available
Verified Repairs(2)
Curtis Hibbs-04/14/2015 | 07:11:41
CORRECTION: Replace the Crankshaft Position (CKP) Sensor.
You Tube - How to change crankshaft sensor in 95 jeep cherokee EASILY!!!!!!
SKILL LEVEL: B
LABOR TIME: 0.5 hrs.
OEM PART NUMBER: 56027280
AFTERMARKET PART: Crankshaft Position Sensor
COMPONENT LOCATION: The Crankshaft Position (CKP) Sensor is located at the rear of the engine on the transmission bellhousing.
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