FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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DTC 134

DTC 134 Chart:




PCM To IPC Wiring Schematic:






CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) uses the serial data line (CKT 800) to communicate with various other components and systems within the vehicle. If the PCM does not receive data from the Instrument Panel Cluster (IPC), the PCM will store DTC 134 indicating loss of communication with the IPC.

DTC 134 WILL SET WHEN
- DTC 12 is not set.
- Engine running for over 20 seconds.
- PCM has detected an IPC communication error for over 5 seconds.

ACTION TAKEN (PCM WILL DEFAULT TO)
With a current DTC 134 stored, the PCM will not be able to communicate with the IPC. DTC 134 does not illuminate the Malfunction Indicator Lamp (MIL) (Service Engine Soon).

DTC 134 WILL CLEAR WHEN
The fault no longer exists.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

1. Checks to see if the Instrument Panel Cluster (IPC) is able to transmit data and ensures that CKT 800 to the IPC is not open.

DIAGNOSTIC AIDS
An intermittent may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation.
Check for:

Poor connection or damaged harness
Inspect vehicle wiring harness, for an open or short to ground in CKT 800, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection, and damaged harness.

Momentary loss of ignition power to IPC
With ignition switch "ON," connect a DVM between IPC harness connector terminal "A10" and ground. Monitor voltage while manipulating harness and ignition key switch. If failure is induced, the voltage will change.

Intermittent test
Observe IPC data on the Tech 1 while moving harness and related connectors. If failure is induced, Tech 1 data will stop updating. This may help to isolate the location of the malfunction.

If, while the vehicle is running, the ignition key is turned to the crank position, the following DTC(s) may set 133, 134, 135 and 136.