claw311

Hello all, I have a 2003 Honda Civic LX 1.7L 5 speed manual that has an extremely strange issue with the cluster. Here's my problem.... Tach works perfect, Speedometer works but is 10mph faster than my actual speed (and no its not cause of my rim/tire size) , temperature gauge goes just above cold but not to where operating temp should be, fuel gauge works but isn't perfectly accurate (it reads full when refueled but doesn't drop till after a few restarts).

The problem doesn't really bother me other than not being able to see the actual temperature to prevent a chance of overheating. When i purchased the car a few months ago, the alternator went and we had a shop install a new one. It wasn't till than that i noticed that the gauges weren't reading exactly accurate. The car does have an aftermarket double din screen which works just fine. I have read through a lot of posts online that hasn't helped much other than process of elimination. Ive ran tests on all fuses but something leaves me to believe that its something simple. Gauges all illuminate and work somewhat but not accurate. The car runs great getting 38mpg even though check engine is light. codes were for both o2 sensors which i replaced but check engine came back on.

Due to the fact that the gauges are all getting power leaves me to believe that the cluster is ok and that sensors (temp, speed, fuel) are sending back data just not accurate. what could it be?

lazlong

Start with the cluster self-diagnostic (post #6): https://honda-tech.com/honda-civic-2...still-3195421/

claw311

Hmmm, I've tried this is the past and it didn't work... Nothing happened. Just tried it a few more times and I'm having trouble reaching any sign of a diagnostic mode. Fuses are all good too

claw311

What I did was held down trip button, turned key to on, then on ll, then off, on, off and pressed the trip 4 times fast. Doesn't work. I wish i knew what i was doing wrong here. I find it difficult to run a diagnostic when the last step turns the key to the off position where it cuts power!?! Anyone have a more simplistic way of explaining this would be much appreciated

thetut

Read the test steps again carefully. It's the LIGHTS switch that you turn on and off during the test.

Former User

claw311

Wow! Ok thanks. Everything checked out according to the diagnostics. Will be looking more into it this weekend

claw311

Ok, so update. still have all the issues even after running cluster diagnostics. I have been quite busy with other fixes lately. i recently found a hairline crack in my radiator so last weekend was dedicated to changing that out. So, now i can focus on this issue again. The car is still running great, all gauges have slight false reading but the tach works accurate. Could it be a bad ground? also, the check engine came right back on after i had the battery out during the radiator swap. Cant seem to get that bugger to go away either. 02 sensors were changed when i bought the car to clear that but same codes keep coming up for both upstream and downstream sensors. I think there is something very stupid tripping out the computer, bad voltage somewhere!?! please help, thanks

claw311

Hey all, I recently started looking into my check engine light issue that might be related to the cluster issue.... I think!?! I ran some test with a multimeter to see if the O2 sensor wiring was getting juice and everything checked out fine. Also, checked the resistance between the sensor itself and everything was good again. My question is why would I be getting check engine codes for 02 sensor failure when they are working fine!?! Has anyone had a similar issue as mine. Wondering if somehow there is an electrical link or ecu issue that could be tripping codes and giving false reading to the cluster? Please help

tech8

1. The speedometer, coolant temperature gauge, and fuel gauge are all controlled by the CPU built-in the gauge assembly.

Speedometer: For non-CVT Civics, the CPU receives pulses from the vehicle speed sensor.

Coolant temp gauge: The CPU receives coolant temperature information from the ECM/PCM via the multiplex control unit. The ECM/PCM receives coolant temperature information from the ECT sensor.

Fuel gauge: The CPU receives fuel level information from the fuel gauge sending unit.

It would be unlikely the VSS, ECT sensor, and fuel gauge sending unit would all be faulty. More likely would be an issue with power or ground supplied to the CPU, or a faulty CPU in the gauge assembly. Along with some other components/circuits, the audio unit and gauge assembly received power via under-hood Fuse no. 9 (10A). There is a possibility the aftermarket double din screen may be affecting power to the gauge assembly. You may want to measure the voltage and if it stays consistent at the Red/Wht wire going to the gauge assembly (Red/Wht wire at terminal pin A16).

In addition, since under-dash Fuse no. 10 (7.5A) also feeds the gauge assembly, you might want to measure the voltage at the Yel wire the gauge assembly (terminal pin A15) while you're at it. Fuse no. 10 doesn't feed the audio unit.

2. Whether they may or may not be related, post the actual OBD-II trouble codes for the O2 sensors.

claw311

Hey, thanks for the speedy reply and input. The codes it throws is P0135 and P0141.

tech8

P0135 is Primary HO2S (sensor 1) heater circuit malfunction
P0141 is Secondary HO2S (sensor 2) heater circuit malfunction

Check under-dash Fuse No. 4 (10A). If that fuse is blown, it can be the cause for the two codes. In addition, power from Fuse No. 4 supplies the ignition input that turns on the alternator/regulator assembly.

If the fuse is not blown, you may want to test the voltage on the separate Blk/Orn wires going to the respective primary A/F sensor and secondary sensor.

There is also another Blk/Orn wire from Fuse No. 4 going to the alternator, that will later connect to a Blk/Yel wire at the alternator. --You may want to see if ~ 12 volts is also there. If there is no, low, or intermittent voltage coming through the Blk/Yel wire to the alternator, the alternator will not charge or have problems charging.

claw311

update: i checked fuse #9 and its all good. I have yet to test the cluster pins due to the short amount of time that i had this past weekend. be back soon with more details, thanks again for the help thus far

Djratrap

I had a similar issue in my 05 VP coupe. My ecu would send out misc codes that were false. Turns out the ECU was fried. I would look into that. The gauge clusters have also been known to randomly stop working/short on the 7th gens.

Tank_EM2

I have a 04 manual trans civic replaced the vss but problem still persists CEL code p0500 ran the self diagnostic check all the needles sweep from minimum to maximum positions all lights operational odometer also works