Temperature fluctuating and oven is not getting warm

Hello

Do you have any error codes ? ERC Failure Codes The oven may stop operating but not give an F-code on the display immediately. F-codes are stored in nonvolatile EEPROM. After 2 identical faults occur consecutively, most F-codes will be displayed (some are never displayed). If displayed, they can be recalled by pressing together:
1. TIMER, 2. CLOCK, and 3. MIN DOWN (or 9).
While displayed, pressing MIN UP or 8 and HR
DOWN or 6 together will clear them. A fault must
exist continuously for 5 minutes before an F-code
is recorded (F2, F8 are sooner).
Electronic Oven Control System
The Electronic Oven Control System consists of
the electronic control (ERC), key panel, oven
sensor, and door lock assembly.

SEE link below for complete service manual

Control Panel
There are 8 basic control panel assemblies. They
can be found listed by model number in the Control
Panel Features section on pages 6 through 16.
Control Panel Access
1. Disconnect the power and open the oven door.
2. Remove 3 screws from across the bottom of
the control panel.
3. Push up on the control panel assembly to
release the top catches.
Note: See special instructions for Glass Touch
Models Only, page 25.
Electronic Range Control (ERC)
Caution: Components are electronically hot on
ERC when voltage is connected to range.
Note: Temperature/Mode Selection is necessary
for operation of relay contacts.
Note: Voltage must be present across terminals
L1 to N for ERC to operate.
There are 7 basic ERC configurations (see illustrations).
The ERC contains the bake and broil
relays, convection relay (some models), control
transformer, lock motor relay (some models),
sensor, and lock motor connector (some models),
along with a series of 1/4-in. terminals for connecting
power to the control and heating units.
BAKE. Press to select the bake function.
2 BROIL HIGH/LOW. Press to select the
broil function.
3 CONV BAKE/MULTI. Press to select baking
with convection on multiple racks.
4 CONV BAKE/1 RACK. Press to select
baking with convection on one rack.
5 CONV ROAST. Press to select roasting with
convection.
6 WARM/PROOF. Press once for warming or
twice for proofing. See the How to Set the
Oven for Warming section and the How to
Set the Oven for Proofing section.
7 START. Must be pressed to start any
cooking or cleaning function.
8 DISPLAY. Shows the operations you have
selected, the time of day and the cooking
or cleaning status.
9 COOK TIME. Use for Timed Bake, Timed
Convection Bake and Timed Convection
Roast operations.
10 DELAY START. Use along with the
COOK TIME or SELF CLEAN STD/LOW
pads to set the oven to start and stop
automatically at a time you select.
11 SELF CLEAN STD/LOW. Press to select
the self-cleaning function. See the Using
the Self-Cleaning Oven section.
12 PROBE. Press when using the probe to
cook food.
13 OVEN LIGHT ON/OFF. Press to turn the
oven lights on or off.
14 CLEAR/OFF. Press to cancel any oven
operation except the clock and timer.
15 TIMER ON/OFF. Press to select the
timer function. The timer does not control
oven operations. The timer can time up to
9 hours and 59 minutes.
16 NUMBER PADS. Use to set any function
requiring numbers—for example, the time
of day on the clock, the timer, the oven
temperature, the internal food temperature,
the starting and length of cooking time for
Timed Bake and the starting and length of
cleaning time for Self-Clean.
17 CLOCK. Press to enter the time of day.