I have a Sonata 2.4l 2002 - the illumination on the cluster panel has failed gone out - what is the remedial action required?

Hello Susan,

Your check engine light is located in your vehicles dash cluster and will only illuminate when a fault is detected..no detected faults..no light, although it should illuminate (to prove it is working) for a short period of time at each engine start up.

If your light does not confirm operation during the start cycle, explore for access to the lights wiring connector behind the instrument panel cluster to see if you can easily remove the lamp from the cluster...sometimes it it easier to remove the dash trim bezels and remove the cluster from the dash to change lamps.

Of course your Toyota's engine management systems are controlled by an computer generally referred to as a ECM (engine control unit (ECU), also commonly called an engine control module) so if your lamp fails to illuminate during the start cycle the problem may not be due to a simple lamp failure.

Principles of Operation
The instrument cluster and panel illumination consists of dimmable and non-dimmable illumination components. The dimmable illumination is controlled by the instrument panel dimmer switch, which allows the brightness level of the backlights to be adjusted to the customer preferences. With the parking lamps ON, the instrument panel dimmer switch uses electronic circuitry to provide a variable pulse width modulated (PWM) output to the instrument panel and all applicable switches depending on the driver-controlled level of intensity. The headlamp switch backlighting consists of 2 constantly illuminated LED bulbs that are powered by separate circuits. Battery voltage is supplied to the first bulb when the ignition switch is in the RUN position. Battery voltage is supplied to the second bulb with the parking lamps ON. The non-dimmable illumination allows for full intensity dependant on the ignition switch position.

Inspection and Verification

1. Verify the customer concern.

1. Visually inspect for obvious signs of mechanical or electrical damage.

Visual Inspection Chart Mechanical Electrical

• Headlamp switch
• Instrument panel dimmer switch

• Circuitry
• Connector(s)
• Headlamp switch
• Instrument panel dimmer switch
• Illumination source(s)

1. If an obvious cause for an observed or reported concern is found, correct he cause (if possible) before proceeding to the next step.

1. If the cause is not visually evident, verify the symptom and GO to Symptom Chart .

Symptom Chart
Symptom Chart Condition Possible Sources Action

• The control illumination is inoperative

• Headlamp switch
• Circuitry

• Go To Pinpoint Test A .

• The instrument cluster illumination is inoperative

• Circuitry
• Instrument cluster

• Go To Pinpoint Test B .

• The climate control panel illumination is inoperative

• Circuitry
• Climate control panel

• Go To Pinpoint Test C .

• The audio unit illumination is inoperative

• Circuitry
• Audio unit

• Go To Pinpoint Test D .

• The transmission control lever illumination is inoperative

• Circuitry
• Transmission control lever illumination bulb

• Go To Pinpoint Test E .

• The hazard warning switch illumination is inoperative

• Circuitry
• Hazard warning switch

• Go To Pinpoint Test F .

• The traction control switch illumination is inoperative

• Circuitry
• Traction control switch

• Go To Pinpoint Test G .

• The window control switch illumination is inoperative

• Circuitry
• Window control switch

• VERIFY the operation of the window control switch in question. If the window control switch is inoperative, REFER to Section 501-11 . If the window control switch operates correctly, INSTALL the new window control switch in question. REFER to Section 501-11 .

• The instrument panel illumination does not dim

• Headlamp switch
• Circuitry

• Go To Pinpoint Test H .

Pinpoint Test B: The Instrument Cluster Illumination Is Inoperative
Normal Operation A variable pulse width modulated (PWM) voltage is supplied to the instrument cluster through circuit 29S-LA31 (OG/BU). The instrument cluster is grounded through circuit 91-GG14 (BK/OG).

Possible Causes
• circuit 29S-LA31 (OG/BU) open
• circuit 91-GG14 (BK/OG) open
• instrument cluster

PINPOINT TEST B: THE INSTRUMENT CLUSTER ILLUMINATION IS INOPERATIVE CAUTION: Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector.

Odometer
The odometer is an electronic digital display. Digits displayed are illuminated by the odometer backlight bulb. The odometer backlight bulb brightness is controlled by class 2 messages from the BCM to adjust the display for daylight and instrument panel dimming operation. The trip odometer and total odometer will show in this display area. The push button in the lower right side of the speedometer is used to toggle between the trip and total odometer readings. To reset the trip odometer, push and hold the button down for at least two seconds. The total odometer display has six digits with no decimal display. The trip odometer has four digits including a decimal point and indicates tenths of a mile or kilometer.
The body control module (BCM) stores the vehicle mileage. If the BCM fails, the cluster will display the last valid mileage that was sent before the BCM failed. For replacement of the BCM refer to the BCM section of this service manual. Replacement instrument clusters do not require odometer pre-setting before installation. If the instrument cluster is replaced, the mileage stored in the BCM will be sent to the new cluster via serial data, and shown in the odometer display.

Your best bet , take it to a qualified repair shop.

If this is for the illumination bulbs in the cluster, that would be the park light fuse in the fuse panel. This should be in a panel under the driver's side dash. At least, that is the set-up for earlier model GM vehicles.

relays etc
try two places
#
up and around the pedals under the dash
#
engine bay cluster of fuses and relay
cover will have the legend of positions

engine light should be on
If the transmission gone to fail safe third and reverse only
faulty ecu / tcu
could be a shift solenoid fault

Hi I'm Rick! I'm afraid you have a cluster problem, the cluster houses the gauge package you see in front of you.. all your gauges operate from the printed circuit board to which they are attached and a portion of that board has failed.. The fix is to replace the cluster.

The problem is electrical. Take/Tow your vehicle to an authorized Hyundai dealership and pay the diagnostic fee... they will tell you exactly what the problem is and the cost of parts/labor to fix it... at least this way you'll know what the problem is and what's required to fix it.

The transistors are BST80, the numbers are just SMD codes, but the reason to make transistor to fail is the illumination layer is faulty. There is also a transformer which may have open circuit You should check that either

not a problem i will say that if that fixed the issue you will need to most likely replace or clean the fuse panel very well.

James

I would start with checking all the fuses. There sould be multaple bulbs in the cluster . there for if all the lights are out it is unlikely a bulb. Make sure you check ALL fuses . Let me know if this helps

James