Pinpoint Test H: The Tachometer Is Inoperative

Instrumentation, Message Center and Warning Chimes

Pinpoint Test H: The Tachometer Is Inoperative

Normal Operation

The PCM uses the Crankshaft Position (CKP) sensor to measure the engine rpm. The PCM sends the Instrument Cluster (IC) the data over the High Speed Controller Area Network (HS-CAN) communication bus to command the tachometer gauge according to the data.

If the IC (Instrument Cluster) does not receive the engine rpm data from the PCM for 5 seconds or less, the IC (Instrument Cluster) defaults the tachometer to the last setting, based upon the last known good rpm message.

If the IC (Instrument Cluster) does not receive the engine rpm data from the PCM for more than 5 seconds or if the data received is deemed invalid, the IC (Instrument Cluster) sets DTC U0100 in continuous memory and defaults the tachometer to 0 rpm.

If the IC (Instrument Cluster) receives invalid data for more than 5 seconds, the IC (Instrument Cluster) sets DTC U2196 and defaults the tachometer to 0 rpm.

NOTE: If DTC U0100 is set in the IC (Instrument Cluster), other observable symptoms may be an inoperative speedometer, temperature gauge or odometer.

This pinpoint test is intended to diagnose the following:

- PCM

- IC (Instrument Cluster)

PINPOINT TEST H : THE TACHOMETER IS INOPERATIVE

H1 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO (Key ON Engine OFF) 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 H2.

H2 CARRY OUT THE TACHOMETER ACTIVE COMMAND USING THE SCAN TOOL

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: IC (Instrument Cluster) DataLogger.

- Select the IC (Instrument Cluster) tachometer (TACH) active command. Command the tachometer on and off while monitoring the tachometer.

Does the tachometer begin at 0 rpm, increase to 8,000 (non-hybrid) or 7,000 rpm (hybrid) then return to 0 rpm?

Yes
GO to H3.

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

H3 RETRIEVE THE RECORDED DTCs FROM THE IC (Instrument Cluster) SELF-TEST

- Check for recorded IC (Instrument Cluster) DTCs from the continuous and on-demand self-tests.

Are any DTCs recorded?

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

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

No
INSTALL a new PCM. TEST the system for normal operation.