Non working fuel gauge and P1432 H C
 

As I’ve read by plenty other people on here... I’m having fuel gauge issues. I have a 97 coupe and the fuel gauge mostly reads empty and the warnings lights like “low fuel” always go off. I checked the DIC and found it has code P1432 H C. my step father replaced the whole drivers side fuel pump/sender assembly a few years back, and that didn’t change anything. Time from time when the gauge may shoot to right above 1/2 way when “full” and time from time it works. It seems to work a lot more when I put sea foam in the gas, and by “more” I mean it may work once or twice... I fill up every 150 ish miles which is about 8-9 gallons. Wondering where exactly I should start; if I should just pull the passenger side sender and clean it along with making sure all the siphon jet pump lines aren’t clogged by blowing in them..?

You can measure signal voltage at the sender plug ,
but I pulled the right sensor last summer on a friends car .
I cleaned the slipring element of the sensor carefully with a eraser and a cleaning solutuion and then checked the resistance with my instruments when finished .
Shall be 40 to 250 ohm empty/full position .

It took me less then one hour to finish the job .
I replaced the old fuel sender seal before I put i back on place

Use a proper tool to disconnect fuel lines from sender .
As shown on the Tech2 the voltage should be approx. 2.5 volt when the passenger tank is full





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Our C5s have a fuel sending unit in each tank. Code P1432 indicates the right side sending unit which is the passenger side tank.

So the passenger fuel level sensor needs to be checked, I also have some weird feeling that tank isn’t getting any gas. Since the gauge doesn’t work much, I fill up every 150 miles. Like I said the gauge will occasionally work, and when it works right after I fill it up (happens a lot actually now) it reads a little above 1/2 a tank.

My guess is that your LH tank allways get fuel . I do not think that the big fuel feed line from the filler get blocked inside.
If the orifice (5) get blocked the siphron pumpwill not work and the level in the LH tank will not change .
This will be indicated by DTC's .
I think your LH sensor needs to be repaired/replaced :)

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Do you mean the right hand side instead of Left hand side ? The code is indicating the right hand side, maybe the passenger tank is full of old gas, and that little Y fuel fitting is clogged, causing the siphon pump to not transfer the fuel, and fuel turned to varnish and corrected the right fuel level sensor ?

The RH (passenger side ) DTC indicates low voltage . Check if you have good ground continuity on the RH sensor
Do Also check the voltage signal on current loop 1937 from the sensor back to the PCM C2:12

Look also here

Here is the description from the manual :

Circuit Description :DTC P1432 Fuel Level Sensor 2 Circuit Low Voltage

The Fuel Level sensor 2, mounted in the rear side of the right fuel tank, measures fuel level changes within the right fuel tank. The Fuel Level sensor 2 has a 5.0 volt reference circuit, a ground, and a signal circuit.

When the fuel level is low the sensor output voltage is high. When the fuel level is high the sensor output voltage is low.

The PCM uses inputs from the Fuel Level sensor 1 and the Fuel Level sensor 2 in order to calculate the total fuel remaining in both fuel tanks. The system sends this information via the serial data to the BCM. This information displays on the fuel gauge.

When the PCM senses a signal voltage lower than the normal operating range of the sensor, this DTC sets.

Conditions for Setting the DTC

• l The Fuel Level sensor voltage is below 0.39 volts.
• l The above condition present for greater than 50 seconds.

Action Taken When the DTC Sets

• l The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails.
• l The malfunction indicator lamp (MIL) will not illuminate.
• l The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

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