P034

DTC PO34:

IAT, MAP And TPS Circuits:

CIRCUIT DESCRIPTION
This diagnostic test monitors the Manifold Absolute Pressure (MAP) signal for loss of engine vacuum under closed throttle conditions. If the difference between MAP signal and the calculated Barometric (BARO) pressure is 11 kPa or less for 15 seconds, Code P034 sets.

TEST CONDITIONS
1. Codes P021, P022, P026, P027, P031, P032, not set.
2. Throttle position switch closed.
3. TP sensor 18 degrees or less.
4. rpm 400 or greater.
5. BARO 75 kPa or greater.

FAILURE CONDITION
Difference between MAP and Calculated BARO is 11 kPa or less for 15 seconds.

ACTION TAKEN
1. Powertrain Control Module (PCM) turns "ON" the Malfunction Indicator Lamp (MIL) (Service Engine Soon).
2. PCM disables long term fuel trim.
3. PCM uses a substitute MAP value based on engine rpm and throttle switch status.
4. PCM disables evaporative emission control solenoid.
5. PCM disables torque management.
6. Transaxle shift adapts are maintained at current levels.

NOTES ON FAULT TREE
1. MAP at idle should be 30-50 kPa, depending on engine load. BARO should be 85-105 kPa, depending on altitude. The difference between the two should always be greater than 11 kPa with the engine running at or near idle.
2. Check for vacuum at the throttle body with a vacuum gage. At idle, typical vacuum readings are 14-20 inches Hg, depending on engine load.
3. PCM data PD02 should read 10-16 kPa with C127 disconnected. If PCM data parameter PD02 reads greater than 16 kPa, check CKT 432 for a short to voltage.
4. Checking for a short to voltage inside the intake manifold.
5. Checking for short to voltage on CKT 452 or CKT 474. Also checking for high resistance on CKT 452. Disconnect C129 to eliminate voltage from transaxle temperature sensor return.