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Intermittent Instrument Panel Gauges

8180 Views 3 Replies 3 Participants Last post by  AJ_Schreiber
Vehicle is a 2003 Dodge Neon with 2.0 L 4 cylinder engine and 4 speed automatic transaxle. Odometer reading is about 227,500 miles. Vehicle is starting to have intermittent operation from certain instrument panel gauges. In particular upon startup the fuel gauge, engine temperature gauge and speedometer will not function. It seems to be random occurrence and happens after the car has set unused for 1 to 8 hours. The speedometer will not function ie. register a speed but the odometer will function and still record distance traveled. All other lamps on the instrument panel function such as panel lamps, turn signal indicator, high beam indicator, check engine lamp.

There is a 26 pin connector on the back side of the instrument panel that provides the electrical connection to the instrument panel. Since some of the lamps work I am thinking that the ground pin #10 must be making proper contact. If it were not making a proper connection, then no electrical item would function on the panel since all must have a proper and good ground????

The check engine lamp illuminates when this no gauge and no speedometer situation occurs. Diagnostic code is P 1681 which I believe means no fuel level bus message.

Last night I removed the instrument panel and cleaned all 26 pins on the panel. I reinstalled the panel started the engine and drove the vehicle and all gauges performed correctly. Problem fixed or so I thought.

This morning I started the vehicle and the same problem surfaced again. The speedometer, fuel gauge and engine temperature gauge would not register properly. Code 1681 is present again. Car sat in a parking lot today and with the summer time heat interior temperatures were probably over 120 deg F. When leaving work started engine and the gauges and speedometer functioned properly.

The signal to drive the engine temperature gauge and speedometer would travel through pin # 2 which is the PCI bus. Pin #7 carries the signal for the fuel gauge driver. Since there are 2 different circuits causing the problem I am thinking that the issue is a poor connection with the 26 way / pin connector.

I am going to remove the instrument panel and ever so slightly bend all the pins so as to make a tighter fit when it is installed. I am thinking that I am just not getting a proper electrical contact on some of the pins???? Or maybe there is a problem with a solder joint(s) on the cluster????

Any thought or ideas welcomed on what to do to fix this issue are welcome.
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1966 Crown Coupe, 2016 200 S AWD, 1962 Lark Daytona V8.
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Many intermittent connections at or on the instrument cluster can be temporarily made to work again by a medium fist 'thump' on top of the dash panel. The mechanical jarring will sometimes 'fix' the bad connection.
Certainly while the cluster is out, gently spread the terminals. A drop of Deoxit and plugging them on and off a few times should scrub the contact surfaces clean. Solder joints and the gauge-to-board terminals can be sprung for firmer contact and Deoxit applied to those contacts as well.
Bad solder joints usually happen at the larger through-hole leads and the fracture may appear as a dark ring around where the lead protrudes from the solder. Touch up any joints that look suspicious.
P1681 is a powertrain fault code (PCI bus) that is between the PCM and cluster. The fuel level signal is sent to the PCM for OBDII reasons. I imagine that a bad connection could occur anywhere in the bus path.

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3,442 Posts
Discussion Starter · #3 ·
ImperialCrown said:
Many intermittent connections at or on the instrument cluster can be temporarily made to work again by a medium fist 'thump' on top of the dash panel. The mechanical jarring will sometimes 'fix' the bad connection.

First thing I did try while driving was a fist on the dash and on the instrument panel. But the panel is mounted securely so I would not expect that to fix the
issue and it did NOT correct it.

I removed the cluster again and used a small, flat blade screwdriver to spread the pins and then scraped each pin thoroughly with the blade. I reassembled and both this morning and evening the cluster gauges and speedometer are functioning as designed.

I will look into the Deoxit. Thanks for the tip!
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