E034

Code E34:

Sensor Circuit:

DESCRIPTION:

This diagnostic test monitors the MAP signal for engine load under closed throttle conditions. If the MAP signal is too high for the closed throttle conditions present when the PCM/ECM monitors the signal, at this time the PCM/ECM would set the code.

TEST CONDITIONS:

1. Codes E21, E22, E26, E27, E31, and E32 not set.
2. Throttle switch closed.
3. Engine speed greater than or equal to 400 RPM.
4. MAP 18 degrees or less.
5. TPS 18 degrees or less.

FAILURE CONDITIONS:

Difference between MAP value and calculated BARO 11 kPa or less for 15 seconds.

ACTION TAKEN:

1. The PCM/ECM illuminates the "SERVICE ENGINE SOON" telltale.
2. PCM/ECM sets BARO at 92kPa and substitutes MAP values on engine speed and throttle switch status.

NOTES ON FAULT TREE:

1. MAP at idle should be 30 to 50 kPa, depending on engine load. BARO should be 85 to 105 kPa, depending upon altitude.

2. Check for vacuum at the MAP sensor hose with a vacuum gauge. At idle, typical vacuum readings are 15" to 20" Hg, depending on engine load.

3. Checking for MAP sensor or MAP circuitry faults.

4. Checking for sensor ground open from sensor to PCM/ECM.

5. Checking for a short to voltage on sensor signal, CKT 432.

6. Fault is most likely at PCM/ECM connector or PCM/ECM. Before replacing the PCM/ECM, perform the "PCM/ECM Replacement Check", CHART C-1.

NOTE ON INTERMITTENTS:

Code E34 is usually set by a vacuum supply problem to the MAP sensor. Check for proper vacuum hose routing. Apply vacuum to the MAP hose and look for vacuum leaks in the MAP hose or MAP sensor. Manipulate affected wiring and connections while observing PCM/ECM parameter P.0.2. Apply and release vacuum to the MAP hose using a vacuum source. If the PCM/ECM parameter P.0.2 jumps or skips high with vacuum applied, the condition has been induced and the cause of the intermittent can be repaired. If wiring and connectors check out OK, substitute a known good MAP sensor and retest.