it is such a code of 4 numbers you have to enter when you try to program new key eather lost or espair
The four digit code for the sentry key system is different for each vehicle. You will need to contact your local dealer with your VIN to get the specific number for your vehicle.
The diagnostic code 12 51 55 is actually not a code for the 1994 Jeep Grand Cherokee Laredo. The 12 means that it has started searching for codes. The 51 is oxygen sensor stuck lean. The 55 means it is finished searching for codes. Getting this means nothing is wrong.
That is a fan relay error. Recommend replacing the relay, these jeeps are notorious for burning them up.
how to fix or check po 206
1990 will require an OBD1 reader
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Trouble code P0720 means:Output speed sensor circuit malfunction
The diagnostic code 12 51 55 is actually not a code for the 1994 Jeep Grand Cherokee Laredo. The 12 means that it has started searching for codes. The 51 is oxygen sensor stuck lean. The 55 means it is finished searching for codes. Getting this means nothing is wrong.
P0725 indicates Engine Speed Input Circuit Malfunction.
The code can be cleared by unhooking the battery. The light will return if the failure is not repaired.
The computer has detected a malfunction and set a trouble code.
Trouble code P0155 means:O2 sensor heater circuit malfunction (Bank 2 Sensor 1)
P0123 TPS volts high. Replace the throttle position sensor.
With a scan tool.With a scan tool.
Trouble code P0320 means: Ignition/Distributor Engine Speed Input Circuit
Basically it means it means you have a invalid skim key and you are going to have to replace the i mobilizer module with new keys and reprogram.
According to Haynes, this represents a misfire in cylinder 6.
That is a fan relay error. Recommend replacing the relay, these jeeps are notorious for burning them up.