Jeep Cherokee (XJ)
- Thumping when setting off may be fixed by greasing the slip yoke
- Radiator quick-connects are prone to leaks
- Automatic transmissions are prone to death by excessive heat on vehicles that have off-road modifications (as these add weight). Installation of a transmission cooler is highly recommended.
- Transmission oil cooler lines can rub and wear through
- If the only window switches that work are the ones located on the driver-side front door, it may be because the window lock switch has shorted out
- Issues related to windows not moving up and/or down may be caused by failed regulators (in which case, you should still hear the window motor) or a broken wire
- No sound coming from the door speakers may be caused by broken wires leading to the speakers
- TSB: Gauges dropping to zero with the engine running or a “No Bus” error message on the gauge cluster may be fixed by installing a new plug and wires behind the instrumental panel
- Climate control issues:
- Air blowing erratically through the dashboard air vents may be caused by a defect in the panel/demist air control actuator (subject to TSB)
- Decreased airflow when climbing a grade (often accompanied by malfunctioning cruise control) may be caused by a vacuum supply circuit leak somewhere between the vacuum bulb reservoir and dash panel vent vacuum motors
Body / Cosmetic
- Squeaking from the cargo/rear seat area may be fixed by greasing the lift gate latch or the latches on the rear seats
- High-mileage vehicles or cars that spent a lot of time off-road may have the body flex so much that the windshield seal breaks open, which allows rainwater to seep in and rust the floorboards
- The bolt that holds the shackle to the unibody is susceptible to rust and broken welds
- Foam inner fender liner can trap dirt and cause seizure of the door strap, premature wear of the door hinges, and damage to the wiring
- Rear quarter windows don’t seal well, allowing water to slowly leak in and collect in the rear lower quarter panels, eventually causing rust/rot
- Door hinges are prone to rot
- The plastic bracket that holds the rear of the center console in place sometimes breaks, causing the arm rest to have excessive movement. This is easy to replace, and an upgrade to a strong steel bracket is recommended for any off-road use.
- All vehicles with AW4 automatic transmissions: If the reverse lights don’t come on or the vehicle throws codes P0700 (Transmission Control System Malfunction) or P0705 (Transmission Range Sensor Malfunction), the Neutral Safety Switch (NSS) is either bad or corroded. Sometimes cleaning it can fix it, but they are often corroded to the shaft that they sit on and are destroyed while taking them off, forcing replacement.
- 4.0L vehicles with the AW4 automatic transmission: A sound similar to rod knock may actually be caused by the flex plate bolts backing out. Remove the inspection plate on the transmission to check the tightness of the bolts. Usually, tightening the bolts will fix the issue, but sometimes they can be damaged and require replacement. If the issue is ignored, then the holes on the flex plate can wallow out, necessitating replacement of the flex plate itself.
- MY87-89: Electrical connector “C-101” is prone to failure from years of water pouring off the hood onto it (subject to TSB)
- When body is extremely flexed, it may not be possible to close doors or the liftgate until the vehicle returns to level ground
Other Tips & Tricks
OBD1 Diagnostic Trouble Codes
On vehicles equipped with OBD1, you can check codes without a scanner using the “blink” method:
- Within 5 seconds: Turn the ignition to the on position, then the off position, then the on position again, then back to the off position.
- The CEL will begin to blink.
- The first sequence of blinks refers to the first digit of the Diagnostic Trouble Code (DTC) – for example, if it blinks twice, that means the number 2.
- There will be a pause in between the first and second numbers.
- The second sequence of blinks refers to the second digit of the DTC – for example, if it blinks four times, that means the number 4.
- If it blinks twice, pauses, then four times, that means it’s saying the vehicle has a DTC of 24.
- If the computer has stored more than one code, there will be a longer pause after the second sequence of numbers, then step 2 will repeat for the new code.