Mercedes-Benz Drive Systems Technician Exam
2026– Verified Questions and Answers
1.
A 2022 Mercedes-Benz E-Class with 4MATIC exhibits unusual vibration at highway speeds.
Technician finds the driveshaft has a 0.006-inch runout. Recommended action:
A. Replace front differential
B. Balance or replace the driveshaft
C. Replace all CV joints
D. Replace rear differential
Correct Answer: B
Rationale:
Even minor driveshaft runout causes vibrations at high speed. Balancing or replacement corrects
the issue before replacing unrelated components.
2.
A Mercedes-Benz EQS reports DTCs P1A2B and P1A3C related to the high-voltage battery.
Technician observes SOC imbalance between modules. Correct first step:
A. Replace entire battery pack
B. Perform module balancing and inspect HV connections
C. Replace inverter
D. Reset vehicle control module
Correct Answer: B
Rationale:
Uneven SOC indicates balancing issues; addressing this prevents unnecessary full battery
replacement.
,3.
A 2021 AMG C43 exhibits intermittent overboost in the twin-scroll turbo system. Technician
finds a leaking vacuum line to the wastegate actuator. Recommended procedure:
A. Replace turbocharger
B. Repair vacuum line and inspect wastegate actuator
C. Replace intake manifold
D. Replace MAF sensor
Correct Answer: B
Rationale:
Vacuum leaks can cause inconsistent boost. Fixing lines and actuator resolves overboost without
replacing the turbo unnecessarily.
4.
During ABS diagnostics on a 2020 GLE 350, the right front wheel speed sensor shows
intermittent readings. Technician inspects the tone ring and finds minor debris. Recommended
step:
A. Replace ABS control module
B. Clean sensor and tone ring
C. Replace wheel bearing
D. Replace master cylinder
Correct Answer: B
Rationale:
Debris often causes intermittent ABS sensor readings; cleaning is the most effective first step.
5.
A 2019 S-Class shows delayed automatic transmission engagement. Technician notes ATF level
is low and slightly contaminated. Recommended action:
,A. Replace transmission
B. Flush fluid, replace filter, and refill with correct ATF
C. Replace torque converter
D. Replace shift solenoids
Correct Answer: B
Rationale:
Low or contaminated fluid commonly causes delayed engagement. Proper service resolves the
issue before replacing hardware.
6.
A 2022 EQC exhibits a “traction control” warning on startup, and the rear wheels spin on low-
friction surfaces. Technician finds wheel speed sensor misalignment on the rear axle. Correct
repair:
A. Replace all wheel bearings
B. Realign wheel speed sensor and check tone ring
C. Replace ABS module
D. Replace the rear differential
Correct Answer: B
Rationale:
Wheel speed sensor misalignment triggers traction control faults. Correcting alignment restores
system function.
7.
During suspension diagnostics on a 2020 E-Class 4MATIC, uneven rear tire wear is noted.
Technician finds worn rear control arm bushings. Recommended repair:
A. Replace bushings and perform full alignment
B. Replace rear tires only
C. Replace rear shocks
D. Lubricate bushings
, Correct Answer: A
Rationale:
Worn bushings affect suspension geometry and tire wear; replacement with alignment is
required.
8.
A 2021 C-Class with mild hybrid system shows intermittent CEL for engine misfire. Technician
notices spark plugs are 50,000 miles old. Correct first step:
A. Replace fuel injectors
B. Replace spark plugs and inspect ignition coils
C. Replace ECM
D. Perform compression test
Correct Answer: B
Rationale:
Spark plug wear is a common cause of misfires. Inspecting coils ensures the ignition system is
functional before more costly replacements.
9.
A 2022 GLE shows judder under acceleration in its 9G-TRONIC automatic transmission. Torque
converter slip is within specifications. Technician suspects internal belt wear. Correct action:
A. Replace torque converter
B. Replace transmission belt
C. Replace ATF only
D. Replace input shaft bearing
Correct Answer: B
Rationale:
Transmission judder with normal torque converter indicates belt wear. Replacement prevents
further damage.
2026– Verified Questions and Answers
1.
A 2022 Mercedes-Benz E-Class with 4MATIC exhibits unusual vibration at highway speeds.
Technician finds the driveshaft has a 0.006-inch runout. Recommended action:
A. Replace front differential
B. Balance or replace the driveshaft
C. Replace all CV joints
D. Replace rear differential
Correct Answer: B
Rationale:
Even minor driveshaft runout causes vibrations at high speed. Balancing or replacement corrects
the issue before replacing unrelated components.
2.
A Mercedes-Benz EQS reports DTCs P1A2B and P1A3C related to the high-voltage battery.
Technician observes SOC imbalance between modules. Correct first step:
A. Replace entire battery pack
B. Perform module balancing and inspect HV connections
C. Replace inverter
D. Reset vehicle control module
Correct Answer: B
Rationale:
Uneven SOC indicates balancing issues; addressing this prevents unnecessary full battery
replacement.
,3.
A 2021 AMG C43 exhibits intermittent overboost in the twin-scroll turbo system. Technician
finds a leaking vacuum line to the wastegate actuator. Recommended procedure:
A. Replace turbocharger
B. Repair vacuum line and inspect wastegate actuator
C. Replace intake manifold
D. Replace MAF sensor
Correct Answer: B
Rationale:
Vacuum leaks can cause inconsistent boost. Fixing lines and actuator resolves overboost without
replacing the turbo unnecessarily.
4.
During ABS diagnostics on a 2020 GLE 350, the right front wheel speed sensor shows
intermittent readings. Technician inspects the tone ring and finds minor debris. Recommended
step:
A. Replace ABS control module
B. Clean sensor and tone ring
C. Replace wheel bearing
D. Replace master cylinder
Correct Answer: B
Rationale:
Debris often causes intermittent ABS sensor readings; cleaning is the most effective first step.
5.
A 2019 S-Class shows delayed automatic transmission engagement. Technician notes ATF level
is low and slightly contaminated. Recommended action:
,A. Replace transmission
B. Flush fluid, replace filter, and refill with correct ATF
C. Replace torque converter
D. Replace shift solenoids
Correct Answer: B
Rationale:
Low or contaminated fluid commonly causes delayed engagement. Proper service resolves the
issue before replacing hardware.
6.
A 2022 EQC exhibits a “traction control” warning on startup, and the rear wheels spin on low-
friction surfaces. Technician finds wheel speed sensor misalignment on the rear axle. Correct
repair:
A. Replace all wheel bearings
B. Realign wheel speed sensor and check tone ring
C. Replace ABS module
D. Replace the rear differential
Correct Answer: B
Rationale:
Wheel speed sensor misalignment triggers traction control faults. Correcting alignment restores
system function.
7.
During suspension diagnostics on a 2020 E-Class 4MATIC, uneven rear tire wear is noted.
Technician finds worn rear control arm bushings. Recommended repair:
A. Replace bushings and perform full alignment
B. Replace rear tires only
C. Replace rear shocks
D. Lubricate bushings
, Correct Answer: A
Rationale:
Worn bushings affect suspension geometry and tire wear; replacement with alignment is
required.
8.
A 2021 C-Class with mild hybrid system shows intermittent CEL for engine misfire. Technician
notices spark plugs are 50,000 miles old. Correct first step:
A. Replace fuel injectors
B. Replace spark plugs and inspect ignition coils
C. Replace ECM
D. Perform compression test
Correct Answer: B
Rationale:
Spark plug wear is a common cause of misfires. Inspecting coils ensures the ignition system is
functional before more costly replacements.
9.
A 2022 GLE shows judder under acceleration in its 9G-TRONIC automatic transmission. Torque
converter slip is within specifications. Technician suspects internal belt wear. Correct action:
A. Replace torque converter
B. Replace transmission belt
C. Replace ATF only
D. Replace input shaft bearing
Correct Answer: B
Rationale:
Transmission judder with normal torque converter indicates belt wear. Replacement prevents
further damage.
