PACCAR MX P0117 is the fault code page for “Coolant Temperature – Voltage too low or short circuit to ground on ECU D420 pin A58” in the 2013 PACCAR MX Diagnostic Service Manual. PACCAR publishes it for engines in the EPA 2013 emissions family, and it is worked with the DAVIE diagnostic software.
What this fault code means
The coolant temperature sensor sits in the coolant return gallery at the right rear end of the cylinder block, and its reading drives fuel quantity and injection timing, torque limiting when coolant is hot, and the cold start aid.
Set and reset conditions
The code sets when the PCI-2 detects sensor output voltage below 0.23 V. It changes to inactive immediately after the diagnostic runs and passes.
PACCAR MX P0117 wiring and technical data
The manual names the two ECU circuits and gives the sensor resistance curve, so a bench measurement separates a bad sensor from bad wiring. The fault code information block records it as 1 trip MIL, 3 drive cycle recovery, readiness group none, freeze frame type Cooling.
| D420 pin | Sensor pin | Function |
|---|---|---|
| A58 | 1 | Signal, coolant temperature |
| A61 | 2 | Ground |
| – | 1 to 2 | 318 to 327 ohm at 80 C |
Possible causes and working notes
- Faulty wiring
- Faulty connector
- Faulty sensor
The step order is short and decisive. Inspect the connectors, then key off, unplug the sensor and read errors in DAVIE: if the low-voltage code stays active replace the sensor; if the high-voltage code appears instead, unplug the PCI harness next. A code still reading low with the harness off points at the PCI, and the manual sends you to the Engine Support Center.
Document details and format
| Field | Value |
|---|---|
| Brand | PACCAR |
| System group | DTCs, MX Engines (EPA2013) |
| Source publication | 2013 PACCAR MX Diagnostic Service Manual |
| Manual page | 131 |
| Pages | 4 |
| File size | 0.6 MB |
| Format | PDF, English |
Applies to PACCAR MX P0117 repairs
The page sits in the DTCs section for MX engines built to the EPA 2013 emissions standard, so it covers trucks running that engine family with the PCI engine control unit. Coverage and dealer support are published on the PACCAR corporate site.
Who needs this PACCAR MX P0117 page
Technicians who want a decision tree rather than guesswork when a coolant temperature circuit reads low on a PACCAR MX engine.
The full PDF page is in the DiagTechPro manuals library; a free account downloads it. Keep the PACCAR MX P0117 sheet open next to DAVIE.
Related manuals library
