Questions and Answers

Jeep Grand Cherokee Stuck In O/D Q. We have a 1995 Jeep Grand Cherokee Laredo with a 4.0 liter engine. It has an automatic transmission with 79,000 miles on it, fuel injected with ABS, P/S, A/C and cruise control. The problem with it started late last fall, when you start the Jeep the O/D light on the dash will stay on and the Jeep starts out in drive, not going to first or second gear. Shifting manually would work.

The motor was dirty so I went and washed it. After three to four weeks of working and not working took to dealer. First time they said they could not find any problems, they told me it had an early version of an electronic shift controller? $65.00 and a day later it started acting up again.

Now the wife said once in a while when the O/D light is not on, the 4x4 light is on and the transmission still is stuck in drive only. Once in a while when the weather is warm and jeep is warm it does fine. Took back to dealer again, this time they said they got a code out of it and it needed a solenoid, which one I don't know, and filter and oil replaced.

$450.00 and one day later is back at it again, this time while no shifting, stays in drive again and now O/D light does not come on some times. I tried the key switch ON-OFF-ON-OFF-ON and the only code that comes up is 55.

Thanks a bunch for any information,
Randy

A. We need to try and get codes out of the Transmission Control Module (TCM). The lamp in the Overdrive OFF switch is used to signal the various flash codes. To view flash codes, proceed as follows:

1. Turn ignition key ON-OFF-ON-OFF-ON finally leaving the key in the ON position. Leave the Overdrive OFF Switch in the normal overdrive (ON) position.
2. Immediately begin counting the number of flashes displayed by the Overdrive OFF Switch indicator lamp.
3. Flash codes will correspond to Powertrain Control Module codes in duration and spacing.
4. A code 55 identifies the end of flash code transmission.

And the possible codes are:

• 11 No Engine Speed Sensor Signal
• 12 No Output Shaft Sensor Signal
• 13 No Vehicle Speed Sensor Signal
• 14 Governor Pressure Sensor Signal
• 15 Throttle Position Signal
• 16 Transmission Temperature Sensor
• 17 Overdrive Off Switch Circuit
• 18 System Voltage Out of Limits
• 19 Standby Voltage Out of Limits
• 21 Governor Pressure Solenoid Circuit
• 22 3-4 Solenoid Circuit
• 23 Torque Converter Clutch Circuit
• 24 Overdrive Off Lamp Circuit
• 25 EEPROM Checksum Error
• 26 Governor Pressure Sensor Offset Drift
• 55 End of Message

If you still get no codes, then we have to explore a mechanical problem inside the transmission. Possibly the overdrive solenoid not venting or a lower valve body malfunction.