PACCAR DTC 57804 is the fault code documented in this extract from the PACCAR Electrical System Service Manual, Section 12, under the heading “Front Drive Axle Oil Temperature Gauge Inoperative”. The section is published as PM819010/KM815054 (04/01/2010) and covers manual pages 12-47 to 12-51. It is a step-by-step diagnostic table, not a general overview.
What PACCAR DTC 57804 means
The manual lists the symptom as the front drive axle oil temperature gauge being inoperative while all other gauges stay operational. The gauge reads through a thermistor sensor. When the diagnostic table shows “Short in axle 1 oil temp circuit”, the manual states the problem could be a short to ground in the wiring between the ICU/CECU and the sensor, or a defective thermistor sensor. Its companion code 57803 (“Open in axle 1 oil temp circuit”) is documented on the same pages.
Document details at a glance
| Brand | PACCAR |
| Model coverage | PACCAR multiplexed cab instrumentation, 2005-2010 |
| System / group | DTCs / Cab (2005-2010) |
| Publication no. | PM819010/KM815054 (04/01/2010) |
| Manual pages | 12-47 to 12-51 |
| PDF pages | 5 |
| File size | 0.2 MB |
| Format / language | PDF, English |
Diagnostic steps in the extract
Every step assumes the Electronic Service Analyst (ESA) diagnostic tool is connected and that the technician already knows how to drive it. The routine connects to the vehicle, monitors the “Front Drive Axle Oil Temperature” component, drives the needle with the Simulate function, then uses Diagnose to read whether PACCAR DTC 57804 is active or inactive.
- CVSG data link daisy chain checks, including Pin 1 to Pin 14 and Pin 3 to Pin 15 of the 52-pin ICU/CECU connector C.
- Continuity from the sensor connector ground wire to the firewall ground stud.
- Continuity from the sensor connector signal wire to Pin 17 of the 52-pin ICU/CECU connector C.
- Unplugging the sensor harness connector to prove whether the short sits in the sensor itself or in the wiring.
- Substituting a known-good gauge and a test ICU/CECU before any part is condemned.
- A sensor resistance table in ohms across the temperature range printed in the manual.
Who needs this PACCAR DTC 57804 procedure
Heavy-duty technicians and workshop owners reach for this section when one gauge dies and the rest of the cluster keeps working. The publication is manufacturer material; current dealer service information is listed on the PACCAR corporate site.
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