Hard Trouble Code E34: Notes

NOTE: If this code is not displayed during second pass of diagnostic codes, it is an intermittent failure and cannot be diagnosed using this procedure.

Trouble code indicates that MAP sensor signal and BARO signal have close to the same value when engine is running at less than wide open throttle. This condition can be observed in engine data display parameters "P.0.2" and "P.0.3" as readings within 6 kPa of each other with engine running at idle. When ignition is on and engine is not cranking or running, both values should be the same. As engine starts to turn over, MAP sensor should register manifold pressure. Possible causes of this condition are: A MAP hose leak or blockage, bad wiring, terminals, etc., or ECM is not able to process signals properly.

NOTE: The following step numbers refer to the numbers in the accompanying flow chart(s).

After verifying failure condition, MAP hose should be inspected for leaks or blockages, and repaired as necessary.
If MAP hose is okay, create low sensor signal by disconnecting MAP sensor. If reading is 17 kPa or greater, then either wiring harness or ECM is shorted to voltage. If no defect is found in circuit No. 432, then short to voltage is either in ECM connector or in ECM itself.
If reading is 14-16 kPa, circuit No. 476X must be checked for an open. If voltage between circuit Nos. 474 and 476X is 0 volts, circuit No. 476X is open. If voltage is 5 volts, ECM and wiring are okay. Fault must be improper mating of sensor terminals or faulty MAP sensor.