Pinpoint Tests AC: The Wait To Start Indicator Is Never/Always On

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test AC: The Wait To Start Indicator Is Never/Always On (Diesel)

Normal Operation

The wait to start signal is transmitted to the Instrument Panel Cluster (IPC) over the High Speed Controller Area Network (HS-CAN) from the PCM. The wait to start indicator illuminates when the key is in the Key ON Engine OFF (KOEO) state indicating that the glow plugs are heating. The IPC internally monitors the wait to start indicator and determines if the indicator is illuminating or not based upon the PCM request and reports if an indicator fault exists back to the PCM. When the glow plugs have sufficiently heated the preheat chamber, the PCM sends a command to the IPC to turn off the wait to start indicator.

If the wait to start request message is missing or invalid for less than 5 seconds, the wait to start indicator remains in the last on/off state, based upon the last known good wait to start request message received.

If the wait to start request message is missing for more than 5 seconds, the IPC sets DTC U0100:00 in continuous memory and defaults the wait to start indicator on.

NOTE: If DTC U0100:00 is set in the IPC, other observable symptoms may be an inoperative speedometer, tachometer or odometer.

This pinpoint test is intended to diagnose the following:

- PCM
- IPC



PINPOINT TEST AC: THE WAIT TO START WARNING INDICATOR IS NEVER/ALWAYS ON (DIESEL)

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AC1 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO SELF-TEST


- Check for recorded PCM DTCs from the Key ON Engine OFF (KOEO) self-test.
- Are any PCM DTCs recorded?

Yes
REFER to Computers and Control Systems Information.

No
GO to AC2.

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AC2 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST


- Check for recorded IPC DTCs from the self-test.
- Is DTC U0100:00 recorded?

Yes
For DTC U0100:00, GO to Pinpoint Test AV. Pinpoint Tests AV: DTC U0100:00

For all other DTCs, REFER to DTC Charts. Instrumentation, Message Center and Warning Chimes

No
GO to AC3.

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AC3 CARRY OUT THE IPC DEALER TEST MODE


- Ignition ON.
- Enter the IPC dealer test mode.
- Scroll through the displays to TELLTALE TEST and monitor the wait to start indicator.
- Does the wait to start indicator illuminate when in the dealer test mode and turn off when in normal operation mode?

Yes
INSTALL a new PCM. REFER to Computers and Control Systems. TEST the system for normal operation.

No
INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). TEST the system for normal operation.

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