PACCAR MX (2004 Emissions) Fault Code: P1051 Grid Heater – Data Erratic, Intermittent, or Incorrect

PACCAR MX (2004 Emissions) Fault Code: P1051 Grid Heater – Data Erratic, Intermittent, or Incorrect

SET CONDITIONS:
The PCI ECU (D420) detects that the boost temperature has risen less than 40?C [104?F] within 20 seconds after activating the glow installation.

DIAGNOSTIC CONDITION:
This diagnostic runs once after the ignition is keyed on and when the glow installation is activated.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive when the fault is no longer detected.

REPAIR VERIFICATION:
1. Clear all DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Faulty glow installation wiring
2. Faulty grid heater relay
3. Faulty glow element

ADDITIONAL INFORMATION:
1. For this diagnostic, the boost temperature is measured at the moment the glow installation (pre and post) is activated and again after 20 seconds. When the glow installation works correctly, the boost temperature is higher after 20 seconds.

2. The PCI activates the glow element (B341) by energizing the grid heater relay (G014).

3. The boost temperature is measured by the boost temperature sensor (F804).