Powertrain Controls - ECM/PCM

Turbo Boost Sensor Circuit High:

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) sends a 5 volt reference signal to the boost sensor. As manifold pressure changes, the electrical resistance of the boost sensor also changes. By monitoring the sensor output voltage, the PCM detects how much pressure is being produced by the turbocharger in the intake manifold. The PCM uses the boost sensor to control turbo boost and fuel at different loads.

DIAGNOSTIC TROUBLE CODE (DTC) 61 Will Set When

^ Boost signal voltage greater than 3.9 volts.
^ RPM less than 3500.

ACTION TAKEN (PCM will default to)
No turbo boost. Poor performance.

DTC 61 WILL CLEAR WHEN
The fault condition(s) no longer exist.

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

1. This step will determine if DTC 61 is the result of a hard failure or an intermittent condition.
2. This step simulates conditions for a DTC 62. If the PCM recognizes the change, the PCM and CKT 432 are OK.
3. This step will check for an open in ground circuit.

DIAGNOSTIC AIDS
With the ignition "ON" and the engine stopped, boost pressure is equal to atmospheric pressure.

Comparison of this reading with a known good vehicle using the same sensor is a good way to check accuracy of a "suspect" sensor. Readings should be the same ± 0.4 volt.

NOTE: Very little boost can be attained by revving the engine in neutral.