Author: Jason
Warning signs of a defective instrument cluster
A bad instrument cluster or speedometer can have many different signs or symptoms. Some warning signs that your instrument cluster is failing include irregular gauge needle movement, erroneous warning lights, and intermittent powering on and off.
Irregular gauge movement
One warning sign your instrument cluster is bad can be irregular gauge movement. The speedometer, RPM, fuel, temperature, oil pressure, oil temperature, transmission temperature, engine voltage, or engine coolant temperature needles can normally fluctuate depending on engine conditions. When these movements become abnormal or incorrect is when problems can start. The first thing to check would be the sensors in the engine to verify the engine is operating correctly. If the engine sensors and wiring has been ruled out then the final remaining option is the instrument cluster. The small servos or motors that physically move the gauge needles can fail. These failures can cause incorrect gauge readings. Use Tanin Electronix General Diagnosis Service to analyze and determine the problems inside your instrument cluster.
Erroneous warning lights
Warning lights that blink or flash inside your instrument cluster are normal. They can signal problems like low washer fluid, low oil level, low fuel level, buckle your seatbelt, and other friendly reminders. Similar to irregular gauge movement, you should check to make sure the washer fluid level is actually filled up or your seatbelt is buckled. It is common for things such as the oil level or pressure sender to stop working, the washer level sensor and the seatbelt reminder light to also fail. You should diagnose these sensors and parts before thinking the instrument cluster is the issue. If all of these items check out then it is possible the instrument cluster needs to be repaired or replaced. For example, on a 2003 and 2004 Toyota 4Runner, if the wrong part number or year cluster is installed then the seatbelt warning light will operate backwards. If you plug in your seatbelt then the light will turn on. If you unplug it then it will turn off. This is an example of an instrument cluster induced problem because someone swapped out the gauge cluster with an incorrect part number. As you can see there are many different ways and symptoms warning lights and indicators in the cluster can be faulty.
Intermittent instrument cluster power on and off
The instrument cluster is a complex computer. It receives many different signals either directly through analog or electronic signals. Newer gauge clusters utilize data lines or CANBUS network information like a computers network cable. Instrument clusters also require multiple low voltage 12 volt power and ground inputs. Instrument clusters can be powered by multiple fuses. We have seen instances where instrument clusters work perfect on our test bench and then a customer plugs it into their car to find out it does not power on. This is almost always an issue with power and grounding. Sometimes an instrument cluster can have up to three to five ground wires and three different fused power wires. It is vital to check your fuse boxes under the dashboard and ensure all fuses are intact. A very common example of this problem that we see is related to Lexus climate control units. One of the fused power wires is shared with the cigarette lighter fuse. The Cigarette lighter is directly underneath the climate control and inside the center console. Coins are known to drop inside this tube and short out the fuse. The fuse blows and then the climate control no longer works. The customer doesn’t think the two are related and is left without a working climate control unit.
Faulty instrument cluster symptom summary
These are just three examples of many that illustrate how instrument clusters can go bad or the sensors around the vehicle can make it seem like the gauge cluster is faulty. Be sure to check all fuses, grounds, and external sensors before assuming the instrument cluster is the cause of your problems. If all else fails contact Tanin Auto Electronix for instrument cluster repair or instrument cluster replacement.