Engine Code AAZ

EGR System, Overview:
Exhaust gas is removed from the exhaust manifold -1- and enters the intake manifold -3- via the EGR vacuum regulator solenoid valve -2-.

Actuation is by vacuum from vacuum pump -4- while control is provided by the automatic glow time control module -J179- (item -8-) via the two-way valve for EGR -N161- (item -5-).

When engine is cold, under full load, certain RPM ranges and at altitudes above 3300 feet, the EGR is switched off as follows:
- At temperatures below +50°C (122°F) and engine is cold, EGR is switched off via sensor for engine temperature -G27- (item -6-).
- The EGR part throttle switch -F166- (item -7-) for EGR (on injection pump) ensures that exhaust gas is only recirculated during part throttle operation.
- Engine speed limiting is affected by automatic glow time control module -J179- (item -8-) and Generator terminal "W" (item -9-). When engine speed exceeds 1200 RPM, EGR is interrupted for 2 seconds. When engine speed exceeds 3200 RPM, EGR is switched off.
- At altitudes over approx. 3300 feet, EGR is switched off by altitude correction features in automatic glow time control module -8-.