Jeep 1997 Grand Cherokee Service Manual page 462

8H - 4 VEHICLE SPEED CONTROL SYSTEM
DIAGNOSIS AND TESTING (Continued)
SPEED CONTROL SYSTEM DIAGNOSTIC TROUBLE CODE DESCRIPTIONS
GENERIC
MIL SCAN
CODE TOOL
CODE
12*
15** P0500
or
P0720
34**
or
or
55*
77**
* Check Engine Lamp (MIL) will not illuminate during engine operation if this Diagnostic Trouble Code was
recorded. Cycle Ignition key as described in manual and observe code flashed by Check Engine lamp.
** Check Engine Lamp (MIL) will be illuminated during engine operation if this Diagnostic Trouble Code
was recorded.
HEX
DRB SCAN TOOL DISPLAY
CODE
Battery Disconnect
23 No Vehicle Speed Sensor Signal
A6 Low Output Spd Sensr RPM,
Above 15 MPH
0F Speed Control Solenoid Circuits
57 Speed Control Switch Always
Low
56 Speed Control Switch Always
High
52 S/C Power Ckt
DESCRIPTION OF DIAGNOSTIC TROUBLE
CODE
Direct battery input to PCM was
disconnected within the last 50 Key-on
cycles.
No vehicle speed sensor signal detected
during road load conditions.
Output shaft speed is less than 60 rpm with
vehicle speed above 15 MPH
An open or shorted condition detected in the
speed control vacuum or vent solenoid
circuits
Speed control switch input below the
minimum
acceptable voltage.
Speed control switch input above the
maximum
acceptable voltage.
Completion of fault code display on Check
Engine lamp.
No power at speed control circuit
ZG