This PACCAR dash dimmer diagnostic codes service manual covers the diagnosis and repair of dimmer circuit faults in PACCAR-equipped trucks manufactured in 2011 and newer. Published by PACCAR, this 2-page electrical system guide addresses inoperative dash dimmer symptoms using the Electronic Service Analyst (ESA) diagnostic tool and provides step-by-step testing procedures for technicians.
The manual focuses on four related diagnostic trouble codes: DTC 148703 (dash dimmer input open), DTC 148704 (dash dimmer input short), DTC 149106 (dash dimmer output short circuit 1), and DTC 149206 (dash dimmer output short circuit 2). Each code corresponds to specific circuit failures in the dimmer control system.
Document details
| Brand | PACCAR |
| Model coverage | PACCAR trucks 2011 and newer (Kenworth, Peterbilt) |
| System/Group | Electrical System / DTCs Cab |
| Publication number | PM819003 / KM815056 |
| Year/Revision | 09/16/2011 |
| Pages | 2 |
| File size | 0.1 MB |
| Format | |
| Language | English |
Table of contents
- Dash Dimmer Input Open or Shorted overview
- Dash Dimmer Output Shorted conditions
- DTC 148703, DTC 148704, DTC 149106, DTC 149206 descriptions
- Symptom: dash dimmer inoperative
- ESA diagnostic tool setup and connection procedure
- Monitor and dimmer rheostat testing
- Step-by-step diagnostic flowchart (Steps 1–7)
- Jumper wire test method for open circuit detection
- Resistance measurement specifications (390–1390 ohms)
- Connector pin identification (52-pin CECU connector C, 9-pin CECU connector A)
- Dimmer control switch testing and replacement guidance
- Short to ground circuit isolation procedures
Applies to
This PACCAR dash dimmer diagnostic codes manual applies to PACCAR-equipped trucks from 2011 and newer model years, including Kenworth and Peterbilt platforms that utilize multiplexed instrumentation controlled by the CECU (Cab Electronic Control Unit). The procedures target vehicles with dash dimmer circuits fed from Pin 5 of the 52-pin connector C and dimmer outputs 1 and 2 from pins 7 and 8 of the 9-pin connector A. For official PACCAR support and additional resources, visit PACCAR official.
Who needs this PACCAR dash dimmer diagnostic codes manual
Diesel truck mechanics, workshop technicians, and shop managers diagnosing inoperative dash dimmer systems on PACCAR trucks require this PACCAR dash dimmer diagnostic codes guide. Technicians performing electrical system repairs using the ESA diagnostic tool will find the step-by-step procedures essential for isolating input opens, shorts to ground, and output circuit failures affecting instrumentation backlighting.
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